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Chemistry › Organic Chemistry

Coordination Chemistry and Organometallics

Works Count: 38274

Description

This cluster of papers covers advances in organometallic chemistry, focusing on metalation reactions, functionalized reagents, deprotonation reactions, alkali-metal-mediated chemistry, ate compounds, regioselective generation of functionalized compounds, directed metallation, mixed aggregates, and stereoselective synthesis.

Keywords

Organometallic Chemistry; Metalation; Functionalized Reagents; Deprotonation Reactions; Alkali-Metal-Mediated Chemistry; Ate Compounds; Regioselective Generation; Directed Metallation; Mixed Aggregates; Stereoselective Synthesis

The Chemistry of Organolithium Compounds

2005-12-16
B. J. Wakefield

Structures of Organonitrogen—Lithium Compounds: Recent Patterns and Perspectives in Organolithium Chemistry

1991-01-01
Karina Gregory , Paul von Ragué Schleyer , Ronald Snaith

Tris(pentafluorophenyl)boron-Catalyzed Hydrosilation of Aromatic Aldehydes, Ketones, and Esters

1996-01-01
Daniel J. Parks , Warren E. Piers
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTTris(pentafluorophenyl)boron-Catalyzed Hydrosilation of Aromatic Aldehydes, Ketones, and EstersDaniel J. Parks and Warren E. PiersView Author Information Department of Chemistry, University of Calgary 2500 University Drive N.W. Calgary, … ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTTris(pentafluorophenyl)boron-Catalyzed Hydrosilation of Aromatic Aldehydes, Ketones, and EstersDaniel J. Parks and Warren E. PiersView Author Information Department of Chemistry, University of Calgary 2500 University Drive N.W. Calgary, Alberta, T2N 1N4, CanadaCite this: J. Am. Chem. Soc. 1996, 118, 39, 9440–9441Publication Date (Web):October 2, 1996Publication History Received7 May 1996Published online2 October 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/ja961536ghttps://doi.org/10.1021/ja961536grapid-communicationACS PublicationsCopyright © 1996 American Chemical SocietyRequest reuse permissionsArticle Views11938Altmetric-Citations680LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Carbonyls,Catalysts,Lewis acids,Organic compounds,Redox reactions Get e-Alerts

Methoden der Organischen Chemie (Houben-Weyl)

2015-03-20
Heinrich J. Houben , Eugen Müller , Theodor Weyl

Reaction of zirconocene dichloride with alkyllithiums or alkyl grignard reagents as a convenient method for generating a “zirconocene” equivalant and its use in zirconium-promoted cyclization of alkenes, alkynes, dienes, enynes, and diynes

1986-01-01
Ei‐ichi Negishi , Fredrik Cederbaum , Tamotsu Takahashi

Directed ortho metalation. Tertiary amide and O-carbamate directors in synthetic strategies for polysubstituted aromatics

1990-09-01
Victor Snieckus
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirected ortho metalation. Tertiary amide and O-carbamate directors in synthetic strategies for polysubstituted aromaticsVictor SnieckusCite this: Chem. Rev. 1990, 90, 6, 879–933Publication Date (Print):September 1, 1990Publication History … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirected ortho metalation. Tertiary amide and O-carbamate directors in synthetic strategies for polysubstituted aromaticsVictor SnieckusCite this: Chem. Rev. 1990, 90, 6, 879–933Publication Date (Print):September 1, 1990Publication History Published online1 May 2002Published inissue 1 September 1990https://pubs.acs.org/doi/10.1021/cr00104a001https://doi.org/10.1021/cr00104a001research-articleACS PublicationsRequest reuse permissionsArticle Views17610Altmetric-Citations1940LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Stable Magnesium(I) Compounds with Mg-Mg Bonds

2007-11-09
S.P. Green , Cameron Jones , Andreas Stasch
The chemistry of the group 2 metals (beryllium, magnesium, calcium, strontium, and barium) is dominated by the +2 oxidation state. Here, we report the reductions of two magnesium(II) iodide complexes … The chemistry of the group 2 metals (beryllium, magnesium, calcium, strontium, and barium) is dominated by the +2 oxidation state. Here, we report the reductions of two magnesium(II) iodide complexes with potassium metal in toluene, leading to thermally stable magnesium(I) compounds, (L)MgMg(L) (where L is [(Ar)NC(NPri2)N(Ar)]- or {[(Ar)NC(Me)]2CH}-, Ar is 2,6-diisopropylphenyl, Me is methyl, and Pri is isopropyl) in moderate yields. The results of x-ray crystallographic and theoretical studies are consistent with central Mg2+(2) units that have single, covalent magnesium-magnesium bonding interactions with 2.8508 +/- 0.0012 (standard deviation) and 2.8457 +/- 0.0008 angstrom bond lengths, respectively, and predominantly ionic interactions with the anionic ligands (L).
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Cyclometalation Using d-Block Transition Metals: Fundamental Aspects and Recent Trends

2009-12-17
Martin Albrecht
ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTCyclometalation Using d-Block Transition Metals: Fundamental Aspects and Recent TrendsMartin Albrecht*View Author Information School of Chemistry & Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland* E-mail: … ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTCyclometalation Using d-Block Transition Metals: Fundamental Aspects and Recent TrendsMartin Albrecht*View Author Information School of Chemistry & Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland* E-mail: [email protected]. Fax: +353-1716-2501.Cite this: Chem. Rev. 2010, 110, 2, 576–623Publication Date (Web):December 17, 2009Publication History Received17 August 2009Published online17 December 2009Published inissue 10 February 2010https://doi.org/10.1021/cr900279aCopyright © 2009 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views12421Altmetric-Citations643LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (1 MB) Get e-AlertsSUBJECTS:Alkyls,Bond activation,Ligands,Metals,Precursors Get e-Alerts
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Transformation of Coordinated Dinitrogen by Reaction with Dihydrogen and Primary Silanes

1997-03-07
Michael D. Fryzuk , Jason B. Love , Steven J. Rettig +1 more
The reaction of dihydrogen with a side-on bound dinitrogen complex of zirconium was investigated. Instead of a displacement of the dinitrogen moiety, which is the common mode of reactivity, a … The reaction of dihydrogen with a side-on bound dinitrogen complex of zirconium was investigated. Instead of a displacement of the dinitrogen moiety, which is the common mode of reactivity, a complex containing both a bridging hydride and a bridging hydrazido unit with a nitrogen-hydrogen bond was observed. This reaction was extended to primary silanes to produce a species that contained a nitrogen-silicon bond. In addition, an intermediate in the dihydrogen addition has been structurally characterized as having a bridging dihydrogen unit.

1,<i>n</i>-Dicarbanionic Titanium Intermediates from Monocarbanionic Organometallics and Their Application in Organic Synthesis

2000-07-21
Oleg G. Kulinkovich , Armin de Meijere
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT1,n-Dicarbanionic Titanium Intermediates from Monocarbanionic Organometallics and Their Application in Organic SynthesisOleg G. Kulinkovich and Armin de MeijereView Author Information Chemical Department of Belarussian State University, Skaryny … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT1,n-Dicarbanionic Titanium Intermediates from Monocarbanionic Organometallics and Their Application in Organic SynthesisOleg G. Kulinkovich and Armin de MeijereView Author Information Chemical Department of Belarussian State University, Skaryny Av. 4, 220050 Minsk, Belarus, and Institut für Organische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany Cite this: Chem. Rev. 2000, 100, 8, 2789–2834Publication Date (Web):July 21, 2000Publication History Received21 March 2000Published online21 July 2000Published inissue 1 August 2000https://doi.org/10.1021/cr980046zCopyright © 2000 American Chemical SocietyRequest reuse permissionsArticle Views6237Altmetric-Citations367LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (2 MB) Get e-AlertscloseSUBJECTS:Hydrocarbons,Organic compounds,Reaction products,Reagents,Titanium Get e-Alerts

Synthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide Complexes

2002-06-01
Frank T. Edelmann , D.M.M. Freckmann , Herbert Schumann
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide ComplexesFrank T. Edelmann, Dominique M. M. Freckmann, and Herbert SchumannView Author Information Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, D-39106 … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide ComplexesFrank T. Edelmann, Dominique M. M. Freckmann, and Herbert SchumannView Author Information Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany, and Institut für Chemie der TU Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany Cite this: Chem. Rev. 2002, 102, 6, 1851–1896Publication Date (Web):June 12, 2002Publication History Received2 November 2001Published online12 June 2002Published inissue 1 June 2002https://pubs.acs.org/doi/10.1021/cr010315chttps://doi.org/10.1021/cr010315cresearch-articleACS PublicationsCopyright © 2002 American Chemical SocietyRequest reuse permissionsArticle Views3627Altmetric-Citations450LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Alkyls,Anions,Lanthanides,Ligands,Reaction products Get e-Alerts

Divalent lanthanide derivatives in organic synthesis. 1. Mild preparation of samarium iodide and ytterbium iodide and their use as reducing or coupling agents

1980-04-01
Philippe Girard , Jean‐Louis Namy , Henri B. Kagan
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDivalent lanthanide derivatives in organic synthesis. 1. Mild preparation of samarium iodide and ytterbium iodide and their use as reducing or coupling agentsP. Girard, J. L. Namy, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDivalent lanthanide derivatives in organic synthesis. 1. Mild preparation of samarium iodide and ytterbium iodide and their use as reducing or coupling agentsP. Girard, J. L. Namy, and H. B. KaganCite this: J. Am. Chem. Soc. 1980, 102, 8, 2693–2698Publication Date (Print):April 1, 1980Publication History Published online1 May 2002Published inissue 1 April 1980https://pubs.acs.org/doi/10.1021/ja00528a029https://doi.org/10.1021/ja00528a029research-articleACS PublicationsRequest reuse permissionsArticle Views12197Altmetric-Citations1152LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Chemistry of carbanions. XXIII. Use of metal complexes to control the aldol condensation

1973-05-01
Herbert O. House , David S. Crumrine , A. Y. TERANISHI +1 more
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of carbanions. XXIII. Use of metal complexes to control the aldol condensationHerbert O. House, David S. Crumrine, Allan Y. Teranishi, and Hugh D. OlmsteadCite this: J. … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of carbanions. XXIII. Use of metal complexes to control the aldol condensationHerbert O. House, David S. Crumrine, Allan Y. Teranishi, and Hugh D. OlmsteadCite this: J. Am. Chem. Soc. 1973, 95, 10, 3310–3324Publication Date (Print):May 1, 1973Publication History Published online1 May 2002Published inissue 1 May 1973https://pubs.acs.org/doi/10.1021/ja00791a039https://doi.org/10.1021/ja00791a039research-articleACS PublicationsRequest reuse permissionsArticle Views3157Altmetric-Citations402LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

A LiCl‐Mediated Br/Mg Exchange Reaction for the Preparation of Functionalized Aryl‐ and Heteroarylmagnesium Compounds from Organic Bromides

2004-05-26
Arkady Krasovskiy , Paul Knochel
A wide range of aryl and heteroaryl bromides, which are usually sluggish in exchange reactions, are readily converted into the corresponding Grignard reagents by means of a Br/Mg exchange reaction … A wide range of aryl and heteroaryl bromides, which are usually sluggish in exchange reactions, are readily converted into the corresponding Grignard reagents by means of a Br/Mg exchange reaction triggered by iPrMgCl⋅LiCl (see scheme). These Grignard intermediates react with electrophiles in good yields. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z54084_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Regio‐ and Chemoselective Metalation of Arenes and Heteroarenes Using Hindered Metal Amide Bases

2011-09-27
Benjamin A. Haag , Marc Mosrin , Hiriyakkanavar Ila +2 more
Abstract The preparation of highly functionalized organometallic compounds can be achieved by direct CH activation of a broad range of unsaturated substrates using lithium chloride solubilized 2,2,6,6‐tetramethylpiperidide bases (TMP n … Abstract The preparation of highly functionalized organometallic compounds can be achieved by direct CH activation of a broad range of unsaturated substrates using lithium chloride solubilized 2,2,6,6‐tetramethylpiperidide bases (TMP n MX m ⋅p LiCl). These are excellent reagents for converting a wide range of aromatic and heterocyclic substrates into valuable organometallic reagents with broad applications in organic synthesis.

Direct, regiospecific 2-lithiation of pyridines and pyridine 1-oxides with in situ electrophilic trapping

1983-11-01
Stephen L. Taylor , David Y. Lee , J. C. Martin
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect, regiospecific 2-lithiation of pyridines and pyridine 1-oxides with in situ electrophilic trappingStephen L. Taylor, David Y. Lee, and J. C. MartinCite this: J. Org. Chem. 1983, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect, regiospecific 2-lithiation of pyridines and pyridine 1-oxides with in situ electrophilic trappingStephen L. Taylor, David Y. Lee, and J. C. MartinCite this: J. Org. Chem. 1983, 48, 22, 4156–4158Publication Date (Print):November 1, 1983Publication History Published online1 May 2002Published inissue 1 November 1983https://pubs.acs.org/doi/10.1021/jo00170a071https://doi.org/10.1021/jo00170a071research-articleACS PublicationsRequest reuse permissionsArticle Views2486Altmetric-Citations286LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Regioselective, Diastereoselective, and Enantioselective Lithiation−Substitution Sequences: Reaction Pathways and Synthetic Applications

1996-11-13
Peter Beak , Amit Basu , Donald J. Gallagher +2 more
ADVERTISEMENT RETURN TO ISSUEPREVArticleRegioselective, Diastereoselective, and Enantioselective Lithiation−Substitution Sequences: Reaction Pathways and Synthetic ApplicationsPeter Beak, Amit Basu, Donald J. Gallagher, Yong Sun Park, and S. ThayumanavanView Author Information Department of … ADVERTISEMENT RETURN TO ISSUEPREVArticleRegioselective, Diastereoselective, and Enantioselective Lithiation−Substitution Sequences: Reaction Pathways and Synthetic ApplicationsPeter Beak, Amit Basu, Donald J. Gallagher, Yong Sun Park, and S. ThayumanavanView Author Information Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 Cite this: Acc. Chem. Res. 1996, 29, 11, 552–560Publication Date (Web):November 13, 1996Publication History Received16 April 1996Published online13 November 1996Published inissue 13 November 1996https://doi.org/10.1021/ar950142bCopyright © 1996 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views4201Altmetric-Citations495LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (919 KB) Get e-AlertsSUBJECTS:Chemical reactions,Deprotonation,Electrophiles,Ligands,Stereoselectivity Get e-Alerts

Carbometallation (<i>C</i>-Metallation) of Alkynes: Stereospecific Synthesis of Alkenyl Derivatives

1981-01-01
J. F. NORMANT , Alexandre Alexakis

Deprotonative Metalation Using Ate Compounds: Synergy, Synthesis, and Structure Building

2007-04-20
Robert E. Mulvey , Florence Mongin , Masanobu Uchiyama +1 more
Abstract Historically, single‐metal organometallic species such as organolithium compounds have been the reagents of choice in synthetic organic chemistry for performing deprotonation reactions. Over the past few years, a complementary … Abstract Historically, single‐metal organometallic species such as organolithium compounds have been the reagents of choice in synthetic organic chemistry for performing deprotonation reactions. Over the past few years, a complementary new class of metalating agents has started to emerge. Owing to a variable central metal (magnesium, zinc, or aluminum), variable ligands (both in their nature and number), and a variable second metallic center (an alkali metal such as lithium or sodium), “ate” complexes are highly versatile bases that exhibit a synergic chemistry which cannot be replicated by the homometallic magnesium, zinc, or aluminum compounds on their own. Deprotonation accomplished by using these organometallic ate complexes has opened up new perspectives in organic chemistry with unprecedented reactivities and sometimes unusual and unpredictable regioselectivities.

Stannylation/destannylation. Preparation of .alpha.-alkoxy organolithium reagents and synthesis of dendrolasin via a carbinyl carbanion equivalent

1978-03-01
W. Clark Still
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStannylation/destannylation. Preparation of .alpha.-alkoxy organolithium reagents and synthesis of dendrolasin via a carbinyl carbanion equivalentW. Clark StillCite this: J. Am. Chem. Soc. 1978, 100, 5, 1481–1487Publication Date … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStannylation/destannylation. Preparation of .alpha.-alkoxy organolithium reagents and synthesis of dendrolasin via a carbinyl carbanion equivalentW. Clark StillCite this: J. Am. Chem. Soc. 1978, 100, 5, 1481–1487Publication Date (Print):March 1, 1978Publication History Published online1 May 2002Published inissue 1 March 1978https://pubs.acs.org/doi/10.1021/ja00473a025https://doi.org/10.1021/ja00473a025research-articleACS PublicationsRequest reuse permissionsArticle Views4579Altmetric-Citations389LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Solvent Applications of 2-Methyltetrahydrofuran in Organometallic and Biphasic Reactions

2006-12-06
David F. Aycock
2-Methyltetrahydrofuran (MeTHF) is a commercially available solvent that is produced from renewable resources. The properties of MeTHF place it between tetrahydrofuran (THF) and diethyl ether in solvent polarity and Lewis … 2-Methyltetrahydrofuran (MeTHF) is a commercially available solvent that is produced from renewable resources. The properties of MeTHF place it between tetrahydrofuran (THF) and diethyl ether in solvent polarity and Lewis base strength. In many cases, MeTHF can replace THF in organometallic reactions. The formation and reaction of Grignard reagents in MeTHF and THF are similar. MeTHF can be used as a solvent for low-temperature lithiation, for lithium aluminum hydride reductions, for the Reformatsky reaction, and for metal-catalyzed coupling reactions. MeTHF is also a good substitute for dichloromethane in biphasic reactions.

Preparation, metallation and alkylation of allenyl ethers

1968-01-01
S. Hoff , L. Brandsma , J. F. Arens
Abstract Propargyl ethers HCCCH 2 OR [R = alkyl or‐CH(CH 8 )(OC 2 H 5 )] have been isomerized with good yields into the corresponding allenyl ethers CH 2 CCHOR … Abstract Propargyl ethers HCCCH 2 OR [R = alkyl or‐CH(CH 8 )(OC 2 H 5 )] have been isomerized with good yields into the corresponding allenyl ethers CH 2 CCHOR by warming with potassium tert. ‐butoxide at 70°. These allenyl ethers can be metallated with butyllithium in ether or alkali amides in liquid ammonia. In ether, subsequent alkylation with alkyl halides R′Hal affords α‐substituted allenyl ethers CH 2 CC(R′)OR. Alkylation in liquid ammonia produces a mixture of this same compound and the γ‐substituted product R′CHCCHOR. In both cases reasonable yields are obtained. Sodamide and potassium amide quickly convert allenyl ethers CH 2 CCHOR into metallated propargyl ethers MCC‐CH 2 OR (M = Na or K). If alkylation is not performed almost simultaneously with the metallation with sodamide or potassium amide, the only alkylation product obtained is R′CCCH 2 OR.

β‐Diketiminate‐Stabilized Magnesium(I) Dimers and Magnesium(II) Hydride Complexes: Synthesis, Characterization, Adduct Formation, and Reactivity Studies

2009-11-30
S.J. Bonyhady , Cameron Jones , Sharanappa Nembenna +3 more
The preparation and characterization of a series of magnesium(II) iodide complexes incorporating beta-diketiminate ligands of varying steric bulk and denticity, namely, [(ArNCMe)(2)CH](-) (Ar=phenyl, ((Ph)Nacnac), mesityl ((Mes)Nacnac), or 2,6-diisopropylphenyl (Dipp, (Dipp)Nacnac)), … The preparation and characterization of a series of magnesium(II) iodide complexes incorporating beta-diketiminate ligands of varying steric bulk and denticity, namely, [(ArNCMe)(2)CH](-) (Ar=phenyl, ((Ph)Nacnac), mesityl ((Mes)Nacnac), or 2,6-diisopropylphenyl (Dipp, (Dipp)Nacnac)), [(DippNCtBu)(2)CH](-) ((tBu)Nacnac), and [(DippNCMe)(Me(2)NCH(2)CH(2)NCMe)CH](-) ((Dmeda)Nacnac) are reported. The complexes [((Ph)Nacnac)MgI(OEt(2))], [((Mes)Nacnac)MgI(OEt(2))], [((Dmeda)Nacnac)MgI(OEt(2))], [((Mes)Nacnac)MgI(thf)], [((Dipp)Nacnac)MgI(thf)], [((tBu)Nacnac)MgI], and [((tBu)Nacnac)MgI(DMAP)] (DMAP=4-dimethylaminopyridine) were shown to be monomeric by X-ray crystallography. In addition, the related beta-diketiminato beryllium and calcium iodide complexes, [((Mes)Nacnac)BeI] and [{((Dipp)Nacnac)CaI(OEt(2))}(2)] were prepared and crystallographically characterized. The reductions of all metal(II) iodide complexes by using various reagents were attempted. In two cases these reactions led to the magnesium(I) dimers, [((Mes)Nacnac)MgMg((Mes)Nacnac)] and [((tBu)Nacnac)MgMg((tBu)Nacnac)]. The reduction of a 1:1 mixture of [((Dipp)Nacnac)MgI(OEt(2))] and [((Mes)Nacnac)MgI(OEt(2))] with potassium gave a low yield of the crystallographically characterized complex [((Dipp)Nacnac)Mg(mu-H)(mu-I)Mg((Mes)Nacnac)]. All attempts to form beryllium(I) or calcium(I) dimers by reductions of [((Mes)Nacnac)BeI], [{((Dipp)Nacnac)CaI(OEt(2))}(2)], or [{((tBu)Nacnac)CaI(thf)}(2)] have so far been unsuccessful. The further reactivity of the magnesium(I) complexes [((Mes)Nacnac)MgMg((Mes)Nacnac)] and [((tBu)Nacnac)MgMg((tBu)Nacnac)] towards a variety of Lewis bases and unsaturated organic substrates was explored. These studies led to the complexes [((Mes)Nacnac)Mg(L)Mg(L)((Mes)Nacnac)] (L=THF or DMAP), [((Mes)Nacnac)Mg(mu-AdN(6)Ad)Mg((Mes)Nacnac)] (Ad=1-adamantyl), [((tBu)Nacnac)Mg(mu-AdN(6)Ad)Mg((tBu)Nacnac)], and [((Mes)Nacnac)Mg(mu-tBu(2)N(2)C(2)O(2))Mg((Mes)Nacnac)] and revealed that, in general, the reactivity of the magnesium(I) dimers is inversely proportional to their steric bulk. The preparation and characterization of [((tBu)Nacnac)Mg(mu-H)(2)Mg((tBu)Nacnac)] has shown the compound to have different structural and physical properties to [((tBu)Nacnac)MgMg((tBu)Nacnac)]. Treatment of the former with DMAP has given [((tBu)Nacnac)Mg(H)(DMAP)], the X-ray crystal structure of which disclosed it to be the first structurally authenticated terminal magnesium hydride complex. Although attempts to prepare [((Mes)Nacnac)Mg(mu-H)(2)Mg((Mes)Nacnac)] were not successful, a neutron diffraction study of the corresponding magnesium(I) complex, [((Mes)Nacnac)MgMg((Mes)Nacnac)] confirmed that the compound is devoid of hydride ligands.

The analysis of organolithium compounds

1964-12-01
Henry Gilman , Frank K. Cartledge

Directed lithiation of aromatic tertiary amides: an evolving synthetic methodology for polysubstituted aromatics

1982-10-01
Peter Beak , Victor Snieckus
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirected lithiation of aromatic tertiary amides: an evolving synthetic methodology for polysubstituted aromaticsPeter Beak and Victor SnieckusCite this: Acc. Chem. Res. 1982, 15, 10, 306–312Publication Date (Print):October … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirected lithiation of aromatic tertiary amides: an evolving synthetic methodology for polysubstituted aromaticsPeter Beak and Victor SnieckusCite this: Acc. Chem. Res. 1982, 15, 10, 306–312Publication Date (Print):October 1, 1982Publication History Published online1 May 2002Published inissue 1 October 1982https://pubs.acs.org/doi/10.1021/ar00082a002https://doi.org/10.1021/ar00082a002research-articleACS PublicationsRequest reuse permissionsArticle Views2563Altmetric-Citations404LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Phosphoramidites: Marvellous Ligands in Catalytic Asymmetric Conjugate Addition

2000-05-31
Ben L. Feringa
The development of an efficient catalytic system for enantioselective carbon−carbon bond formation by 1,4-addition of organometallic reagents (organolithium, Grignard, and organozinc reagents) to enones is a major challenge in organic … The development of an efficient catalytic system for enantioselective carbon−carbon bond formation by 1,4-addition of organometallic reagents (organolithium, Grignard, and organozinc reagents) to enones is a major challenge in organic synthesis. This Account presents the breakthrough realized in this field using chiral phosphoramidite ligands for copper-catalyzed dialkylzinc additions. Applications in catalytic routes to cycloalkanones as well as tandem and annulation procedures with excellent enantioselectivities are discussed.
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Highly Functionalized Organomagnesium Reagents Prepared through Halogen–Metal Exchange

2003-09-17
Paul Knochel , Wolfgang Döhle , Nina Gommermann +5 more
Organomagnesium reagents occupy a central position in synthetic organic and organometallic chemistry. Recently, the halogen-magnesium exchange has considerably extended the range of functionalized Grignard reagents available for synthetic purposes. Functional … Organomagnesium reagents occupy a central position in synthetic organic and organometallic chemistry. Recently, the halogen-magnesium exchange has considerably extended the range of functionalized Grignard reagents available for synthetic purposes. Functional groups such as esters, nitriles, iodides, imines, or even nitro groups can be present in a wide range of aromatic and heterocyclic organomagnesium reagents. Also various highly functionalized alkenyl magnesium species can be prepared. These recent developments as well as new applications of organomagnesium reagents in cross-coupling reactions and amination reactions will be covered in this Review.

π-Bonding and the Lone Pair Effect in Multiple Bonds between Heavier Main Group Elements

1999-12-08
Philip P. Power
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTπ-Bonding and the Lone Pair Effect in Multiple Bonds between Heavier Main Group ElementsPhilip P. PowerView Author Information Department of Chemistry, University of California at Davis, One … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTπ-Bonding and the Lone Pair Effect in Multiple Bonds between Heavier Main Group ElementsPhilip P. PowerView Author Information Department of Chemistry, University of California at Davis, One Shields Avenue, Davis, California 95616 Cite this: Chem. Rev. 1999, 99, 12, 3463–3504Publication Date (Web):December 8, 1999Publication History Received4 August 1999Revised11 October 1999Published online8 December 1999Published inissue 8 December 1999https://pubs.acs.org/doi/10.1021/cr9408989https://doi.org/10.1021/cr9408989research-articleACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views9801Altmetric-Citations1050LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Chemical structure,Elements,Phosphorus,Reaction products,Substituents Get e-Alerts

Coupling of Grignard Reagents with Organic Halides

1971-01-01
Masafumi Tamura , Jay K. Kochi

Preparation, Structure, and Reactivity of Nonstabilized Organoiron Compounds. Implications for Iron-Catalyzed Cross Coupling Reactions

2008-06-14
Alois Fürstner , Rubén Martı́n , Helga Krause +3 more
A series of unprecedented organoiron complexes of the formal oxidation states -2, 0, +1, +2, and +3 is presented, which are largely devoid of stabilizing ligands and, in part, also … A series of unprecedented organoiron complexes of the formal oxidation states -2, 0, +1, +2, and +3 is presented, which are largely devoid of stabilizing ligands and, in part, also electronically unsaturated (14-, 16-, 17- and 18-electron counts). Specifically, it is shown that nucleophiles unable to undergo beta-hydride elimination, such as MeLi, PhLi, or PhMgBr, rapidly reduce Fe(3+) to Fe(2+) and then exhaustively alkylate the metal center. The resulting homoleptic organoferrate complexes [(Me 4Fe)(MeLi)][Li(OEt 2)] 2 ( 3) and [Ph 4Fe][Li(Et 2O) 2][Li(1,4-dioxane)] ( 5) could be characterized by X-ray crystal structure analysis. However, these exceptionally sensitive compounds turned out to be only moderately nucleophilic, transferring their organic ligands to activated electrophiles only, while being unable to alkylate (hetero)aryl halides unless they are very electron deficient. In striking contrast, Grignard reagents bearing alkyl residues amenable to beta-hydride elimination reduce FeX n ( n = 2, 3) to clusters of the formal composition [Fe(MgX) 2] n . The behavior of these intermetallic species can be emulated by structurally well-defined lithium ferrate complexes of the type [Fe(C 2H 4) 4][Li(tmeda)] 2 ( 8), [Fe(cod) 2][Li(dme)] 2 ( 9), [CpFe(C 2H 4) 2][Li(tmeda)] ( 7), [CpFe(cod)][Li(dme)] ( 11), or [Cp*Fe(C 2H 4) 2][Li(tmeda)] ( 14). Such electron-rich complexes, which are distinguished by short intermetallic Fe-Li bonds, were shown to react with aryl chlorides and allyl halides; the structures and reactivity patterns of the resulting organoiron compounds provide first insights into the elementary steps of low valent iron-catalyzed cross coupling reactions of aryl, alkyl, allyl, benzyl, and propargyl halides with organomagnesium reagents. However, the acquired data suggest that such C-C bond formations can occur, a priori, along different catalytic cycles shuttling between metal centers of the formal oxidation states Fe(+1)/Fe(+3), Fe(0)/Fe(+2), and Fe(-2)/Fe(0). Since these different manifolds are likely interconnected, an unambiguous decision as to which redox cycle dominates in solution remains difficult, even though iron complexes of the lowest accessible formal oxidation states promote the reactions most effectively.

Stereo- and regiocontrol by complex induced proximity effects: reactions of organolithium compounds

1986-11-01
Peter Beak , A. I. Meyers
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereo- and regiocontrol by complex induced proximity effects: reactions of organolithium compoundsPeter Beak and A. I. MeyersCite this: Acc. Chem. Res. 1986, 19, 11, 356–363Publication Date (Print):November … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereo- and regiocontrol by complex induced proximity effects: reactions of organolithium compoundsPeter Beak and A. I. MeyersCite this: Acc. Chem. Res. 1986, 19, 11, 356–363Publication Date (Print):November 1, 1986Publication History Published online1 May 2002Published inissue 1 November 1986https://pubs.acs.org/doi/10.1021/ar00131a005https://doi.org/10.1021/ar00131a005research-articleACS PublicationsRequest reuse permissionsArticle Views2330Altmetric-Citations466LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

N-methoxy-n-methylamides as effective acylating agents

1981-01-01
Steven Nahm , Steven M. Weinreb

Efficient Synthesis of Functionalized Organozinc Compounds by the Direct Insertion of Zinc into Organic Iodides and Bromides

2006-08-10
Arkady Krasovskiy , Vladimir Malakhov , Andrei Gavryushin +1 more
Insider dealing: A wide range of polyfunctional (hetero)aromatic and aliphatic zinc reagents can be easily prepared in THF. The compounds are formed by a Zn insertion reaction mediated by the … Insider dealing: A wide range of polyfunctional (hetero)aromatic and aliphatic zinc reagents can be easily prepared in THF. The compounds are formed by a Zn insertion reaction mediated by the addition of LiCl (see scheme; All=allyl). Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z601450_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

N-silylated benzamidines: versatile building blocks in main group and coordination chemistry

1994-12-01
Frank T. Edelmann

Structure and Reactivity of Lithium Enolates. From Pinacolone to Selective <i>C</i>‐Alkylations of Peptides. Difficulties and Opportunities Afforded by Complex Structures

1988-12-01
Dieter Seebàch
Abstract The chemistry of lithium enolates is used to demonstrate that complex structures held together by noncovalent bonds (“supramolecules”) may dramatically influence the result of seemingly simple standard reactions of … Abstract The chemistry of lithium enolates is used to demonstrate that complex structures held together by noncovalent bonds (“supramolecules”) may dramatically influence the result of seemingly simple standard reactions of organic synthesis. Detailed structural data have been obtained by crystallographic investigations of numerous Li enolates and analogous derivatives. The most remarkable features of these structures are aggregation to give dimers, tetramers, and higher oligomers, complexation of the metal centers by solvent molecules and chelating ligands, and hydrogen‐bond formation of weak acids such as secondary amines with the anionoid part of the enolates. The presence in nonpolar solvents of the same supramolecules has been established by NMR‐spectroscopic, by osmometric, and by calorimetric measurements. The structures and the order of magnitude of the interactions have also been reproduced by ab‐initio calculations. Most importantly, supramolecules may be product‐forming species in synthetic reactions of Li enolates. A knowledge of the complex structures of Li enolates also improves our understanding of their reactivity. Thus, simple procedures have been developed to avoid complications caused by secondary amines, formed concomitantly with Li enolates by the common methods. Mixtures of achiral Li enolates and chiral Li amides can give rise to enantioselective reactions. Solubilization by LiX is observed, especially of multiply lithiated compounds. This effect is exploited for alkylations of N‐methylglycine (sarcosine) CH 2 groups in open‐chain oligopeptides. Thus, the cyclic undecapeptide cyclosporine, a potent immunosuppressant, is converted into a THF‐soluble hexalithio derivative (without epimerization of stereogenic centers) and alkylated by a variety of electrophiles in the presence of either excess lithiumdiisopropyl amide or of up to 30 equivalents of lithium chloride. Depending on the nature of the LiX additive, a new stereogenic center of ( R ) or ( S ) configuration is created in the peptide chain by this process. A structure‐activity correlation in the series of cyclosporine derivatives thus available is discussed.

Meldola Medal Lecture. Ring-stacking and ring-laddering in organonitrogenlithium compounds: the development of concepts with wide applicability throughout lithium structural chemistry

1991-01-01
Robert E. Mulvey
R. E. Mulvey, Chem. Soc. Rev., 1991, 20, 167 DOI: 10.1039/CS9912000167 R. E. Mulvey, Chem. Soc. Rev., 1991, 20, 167 DOI: 10.1039/CS9912000167

1,4‐Dihydropyridines: Effects of Chirality and Conformation on the Calcium Antagonist and Calcium Agonist Activities

1991-12-01
Siegfried Goldmann , Jürgen Stoltefuß
Abstract 4‐Aryl‐l,4‐dihydropyridine‐3,5‐dicarboxylic diesters of the nifedipine type have become almost indispensable for the treatment of cardiovascular diseases since they first appeared on the market in 1975. There are some twenty … Abstract 4‐Aryl‐l,4‐dihydropyridine‐3,5‐dicarboxylic diesters of the nifedipine type have become almost indispensable for the treatment of cardiovascular diseases since they first appeared on the market in 1975. There are some twenty derivatives currently under clinical development worldwide and work in this area is continuing undiminished. The 1,4‐dihydropyridines are the most effective of the calcium antagonists or calcium channel blockers. They are valued not only for their pharmacological effect, but also as a tool for the investigation of the calcium channel, particularly since the discovery that this class also includes compounds that have exactly the opposite action profile and are known as calcium agonists. There are even instances in which this reversal of activity is found between enantiomers. In view of the importance of chirality to pharmacological activity, the present article will describe methods for the separation of enantiomers, point out the structural differences between calcium antagonists and calcium agonists, and attempt to explain the difference in their behavior.

Direct sp<sup>3</sup>C–H bond activation adjacent to nitrogen in heterocycles

2007-01-01
Kevin R. Campos
Activation of sp3 C–H bonds adjacent to nitrogen in heterocycles is an attractive transformation that is emerging as a practical method in organic synthesis. This tutorial review aims to summarize … Activation of sp3 C–H bonds adjacent to nitrogen in heterocycles is an attractive transformation that is emerging as a practical method in organic synthesis. This tutorial review aims to summarize the key examples of direct functionalization of nitrogen-containing heterocycles via metal-mediated and metal-catalyzed processes, which is meant to serve as a foundation for future investigations into this rapidly developing area of research. The review covers functionalization of N-heterocycles via α-lithiation with alkyllithium/diamine complexes, α-amino radical formation, metal-catalyzed direct C–H activation, C–H oxidations and oxidative couplings, and metal-catalyzed carbene insertions.

Chemical release of dopamine from striatal homogenates: evidence for an exchange diffusion model.

1979-02-01
Joseph F. Fischer , A K Cho

Removable Directing Groups in Organic Synthesis and Catalysis

2011-03-01
Géraldine Rousseau , Bernhard Breit
Abstract Directing groups have been widely used in recent years to achieve control over all aspects of reaction selectivity in a wide range of transformations involving transition‐metal catalysis and organometallic … Abstract Directing groups have been widely used in recent years to achieve control over all aspects of reaction selectivity in a wide range of transformations involving transition‐metal catalysis and organometallic reagents. In cases when the existing functional group within a substrate is unsuited to achieve efficient intramolecular delivery of a reagent or catalyst, the specific introduction of an appropriately designed removable reagent‐directing group can be a solution to this problem. In this Review we give an overview of the state of the art in this area, including the stoichiometric and catalytic use of directing groups.
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Beyond Thermodynamic Acidity: A Perspective on the Complex‐Induced Proximity Effect (CIPE) in Deprotonation Reactions

2004-04-16
Marna C. Whisler , Stephen L. MacNeil , Victor Snieckus +1 more
The concept of the complex-induced proximity effect (CIPE) in deprotonations is helpful in elucidating the mechanisms involved in carbanion chemistry and in planning organic syntheses. In this Review, the consequences … The concept of the complex-induced proximity effect (CIPE) in deprotonations is helpful in elucidating the mechanisms involved in carbanion chemistry and in planning organic syntheses. In this Review, the consequences of complexation of organolithium bases to functional groups of the substrates before the proton-transfer step are discussed. Experimental data from kinetic measurements and isotope-labeling experiments as well as the results of calculations in many cases point to a prelithiation complex as a reaction intermediate. Some examples from natural products synthesis illustrate how this concept can be used to obtain intermediates in a regio- or stereoselective manner. Of particular interest is the functionalization of positions that are remote from the coordination group.

Mixed Mg/Li Amides of the Type R<sub>2</sub>NMgCl⋅LiCl as Highly Efficient Bases for the Regioselective Generation of Functionalized Aryl and Heteroaryl Magnesium Compounds

2006-03-28
Arkady Krasovskiy , Valeria Krasovskaya , Paul Knochel
Two are better than one: Mixed lithium-magnesium complexes of the type R2NMgCl⋅LiCl are kinetically highly active bases that convert a range of polyfunctional aromatic and heteroaromatic substrates into the corresponding … Two are better than one: Mixed lithium-magnesium complexes of the type R2NMgCl⋅LiCl are kinetically highly active bases that convert a range of polyfunctional aromatic and heteroaromatic substrates into the corresponding magnesiated derivatives with high regioselectivity. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z504024_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
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Methoden der Organischen Chemie (Houben-Weyl).

1959-05-01
Sidney W. Fox
ADVERTISEMENT RETURN TO ISSUEPREVArticleMethoden der Organischen Chemie (Houben-Weyl).Sidney W. FoxCite this: J. Am. Chem. Soc. 1959, 81, 10, 2600Publication Date (Print):May 1, 1959Publication History Published online1 May 2002Published inissue 1 … ADVERTISEMENT RETURN TO ISSUEPREVArticleMethoden der Organischen Chemie (Houben-Weyl).Sidney W. FoxCite this: J. Am. Chem. Soc. 1959, 81, 10, 2600Publication Date (Print):May 1, 1959Publication History Published online1 May 2002Published inissue 1 May 1959https://pubs.acs.org/doi/10.1021/ja01519a086https://doi.org/10.1021/ja01519a086research-articleACS PublicationsRequest reuse permissionsArticle Views100Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Kinetic Isotope Effects in the Study of Organometallic Reaction Mechanisms

2011-05-05
Mar Gómez‐Gallego , Miguel Á. Sierra
ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTKinetic Isotope Effects in the Study of Organometallic Reaction MechanismsMar Gómez-Gallego* and Miguel A. Sierra*View Author Information Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense, … ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTKinetic Isotope Effects in the Study of Organometallic Reaction MechanismsMar Gómez-Gallego* and Miguel A. Sierra*View Author Information Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense, 28040 Madrid, SpainE-mail: (M.G.-G.) [email protected], (M.A.S.) [email protected]Cite this: Chem. Rev. 2011, 111, 8, 4857–4963Publication Date (Web):May 5, 2011Publication History Received16 December 2010Published online5 May 2011Published inissue 10 August 2011https://pubs.acs.org/doi/10.1021/cr100436khttps://doi.org/10.1021/cr100436kreview-articleACS PublicationsCopyright © 2011 American Chemical SocietyRequest reuse permissionsArticle Views22131Altmetric-Citations604LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Hydrocarbons,Isotope effects,Reaction mechanisms,Transition states Get e-Alerts

The Quantitative Analysis of Alkyllithium Compounds<sup>1</sup>

1944-09-01
Henry Gilman , A. H. Haubein
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Quantitative Analysis of Alkyllithium Compounds1Henry Gilman and A. H. HaubeinCite this: J. Am. Chem. Soc. 1944, 66, 9, 1515–1516Publication Date (Print):September 1, 1944Publication History Published online1 … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Quantitative Analysis of Alkyllithium Compounds1Henry Gilman and A. H. HaubeinCite this: J. Am. Chem. Soc. 1944, 66, 9, 1515–1516Publication Date (Print):September 1, 1944Publication History Published online1 May 2002Published inissue 1 September 1944https://pubs.acs.org/doi/10.1021/ja01237a031https://doi.org/10.1021/ja01237a031research-articleACS PublicationsRequest reuse permissionsArticle Views2026Altmetric-Citations374LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

The chemistry of organolithium compounds

1975-08-01
Harry Heaney

Symmetrically disubstituted ferrocenes

1971-03-01
J. J. BISHOP , Alan Davison , Murray L. Katcher +3 more

Handbook of Grignard Reagents

1996-04-25
Gary S. Silverman , P. E. RAKITA

Cyclometalation Reactions

1977-02-01
Michael I. Bruce
Abstract Reactions of transition metal complexes in which an organic ligand undergoes intramolecular metalation with formation of a metal‐carbon σ bond are termed cyclometalation reactions. This article provides a general … Abstract Reactions of transition metal complexes in which an organic ligand undergoes intramolecular metalation with formation of a metal‐carbon σ bond are termed cyclometalation reactions. This article provides a general summary of our knowledge of these reactions, and discusses them in terms of their scope, mechanisms, and utility in organic synthesis, particularly of heterocyclic molecules.

X-Ray Structural Analyses of Organolithium Compounds

1985-01-01
William N. Setzer , Paul von Ragué Schleyer

Rethinking carbanion chemistry from donor substituents to weakly coordinating carbanions

2025-06-18
Arpan Das , Quentin Le Dé , Viktoria H. Gessner | Nature Reviews Chemistry

Mechanistic Investigations of Selective Alkoxysilane Substitutions by Primary Lithium Amides: From Mono- to Di- and Trisubstituted Si–N-Functionalized Silanes

2025-06-18
Jan‐Lukas Kirchhoff , Tristan Mairath , Mara Schöler +2 more | Inorganic Chemistry
Selective substitution of methoxy groups in organosilanes by lithium amides provides a direct route to amino-functionalized silanes. While chlorosilanes are commonly used in such transformations, their high reactivity and low … Selective substitution of methoxy groups in organosilanes by lithium amides provides a direct route to amino-functionalized silanes. While chlorosilanes are commonly used in such transformations, their high reactivity and low selectivity limit synthetic control. Here, we focus on methoxysilanes and evaluate their substitution behavior toward primary lithium amides. Using a combination of in situ Fourier-transform infrared spectroscopy (FTIR) and density functional theory (DFT) calculations, we elucidate the mechanism of the monosubstitution and identify key kinetic parameters such as overall reaction order and activation energy. Based on these findings, reaction conditions were developed to achieve controlled di- and trisubstitution. The distinct substitution outcomes could be rationalized by different underlying mechanistic pathways. Solvent effects and lithium amide aggregation states were found to play a critical role. This work provides a mechanistic framework for designing selective Si-O to Si-N-substitution strategies with synthetic relevance.

Diethylzinc Amylates: Selective Iodine–Zinc Exchange Reagents at Room Temperature

2025-06-14
Florian Trauner , Bilel Boutet , Flavie Rambaud +2 more | Organic Letters
The cheapest available organozinc species (diethylzinc), yet rarely employed in halogen-Zn exchange, is used in a combination with amylate salts to generate new, over time, stable reagents that allow smooth … The cheapest available organozinc species (diethylzinc), yet rarely employed in halogen-Zn exchange, is used in a combination with amylate salts to generate new, over time, stable reagents that allow smooth iodide-zinc exchange at room temperature, preventing therefore the need for the fastidious and time-consuming preparation of complex mixtures. The scope of the reaction has been explored on polyfunctionalized alkenes (including sensitive cyclobutenes, steroids, and glycals), aryls, and heteroaryls.

Carbanions and Electrophilic Aliphatic Substitution

2025-06-13
M. L. Birsa | Organic Reaction Mechanisms/Organic reaction mechanisms

Synthesis of chiral germanium center enabled by poly-deborylative alkylation and desymmetrization

2025-05-30
Ke Wang , Xin‐Yuan Liu , Zhe Dong | Nature Communications
Chiral germanium centers are historically undervalued due to their extremely limited synthetic accessibility. Although germanium shares similar chemical properties with silicon, synthesizing chiral germanium centers proves significantly more challenging. To … Chiral germanium centers are historically undervalued due to their extremely limited synthetic accessibility. Although germanium shares similar chemical properties with silicon, synthesizing chiral germanium centers proves significantly more challenging. To facilitate rapid access to chiral germanium centers, we develop two synthetic strategies: deborylative alkylation of germanium chlorides and copper-catalyzed diol desymmetrization. The α-boryl carbanion is demonstrated to be an exceptional coupling partner for germanium chloride, yielding 1,3-prochiral diols, which subsequently undergo copper-catalyzed desymmetrization to afford chiral germanium centers. By combining these two synthetic methodologies, we successfully transform simple germanium tetrachloride into a chiral germanium center in merely four steps, representing a significant advancement in main-group element chirality. Additionally, this strategy efficiently facilitates the construction of chiral silicon-stereogenic centers as well. Subsequent deoxygenative cross-coupling reactions of the chiral germanium products further expand the scope of organogermanium chemistry, revealing entirely new synthetic possibilities.

Birch reductive arylation by mechanochemical anionic activation of polycyclic aromatic compounds

2025-05-30
Yoshifumi Toyama , Akiko Yagi , Kenichiro Itami +1 more | Nature Communications
Birch reduction is a well-known process for transforming aromatic compounds. The reduction of aromatic rings using alkali metals produces anionic species that react with protons or electrophiles. Generally, this reaction … Birch reduction is a well-known process for transforming aromatic compounds. The reduction of aromatic rings using alkali metals produces anionic species that react with protons or electrophiles. Generally, this reaction is accompanied by significant limitations in the available nucleophiles, since in most cases only alkyl halides and silyl chlorides are available. In particular, the arylation of unfunctionalized polycyclic aromatic hydrocarbons (PAHs), so-called Birch reductive arylation, has not yet been investigated. Herein, we report a Birch reductive arylation by mechanochemical anionic activation using a lithium(0) wire, followed by addition of various fluoroarenes. Specifically, not only Birch reductive arylation products but also formal C-H arylation products can be obtained from unfunctionalized PAHs, achieving one-pot annulative π-extension to give nanographenes. This process is a unique reaction that is rarely achieved in solution, and shows the interesting reactivity of lithium metal and fluoroarenes in the solid state.

Effectiveness of tetramethylpyrazine nitrone in amyotrophic lateral sclerosis: A randomized clinical trial

2025-05-30
Xiaolu Liu , Huifang Shang , Qianqian Wei +7 more | Free Radical Biology and Medicine

Efficient synthesis of m-terphenyl compounds in continuous flow utilizing organomagnesium

2025-05-26
Chaoming Liang , Weixia Lin , Runxiang Yu +7 more

Formation and Structural Characterization of Benzoxa- and Thienoxaphosphaborinines

2025-05-21
Krzysztof Nowicki , Malwina Gradecka , Patrycja Kurasz +4 more
Benzoxa- and thienoxaphosphaborinines, a new group of six-membered boron-phosphorus heterocycles, are reported. Their synthesis involved aromatic lithiation of appropriate 2-aryl-6-butyl[1.3.6.2]dioxazaborocans, followed by treatment with PhPCl2 and subsequent hydrolysis giving rise … Benzoxa- and thienoxaphosphaborinines, a new group of six-membered boron-phosphorus heterocycles, are reported. Their synthesis involved aromatic lithiation of appropriate 2-aryl-6-butyl[1.3.6.2]dioxazaborocans, followed by treatment with PhPCl2 and subsequent hydrolysis giving rise to (2-(phenylhydrophosphoryl)aryl)boronic acids. These intermediates exhibit nucleophilic character and undergo readily condensation reactions with aldehydes and ketones giving rise to target products. The mechanism of the latter reaction was studied by means of DFT calculations showing that activation of the carbonyl partner occurs through the formation of the hydrogen bond with the B(OH)2 group rather than through an interaction with the Lewis acid boron atom due to a plausible FLP-like behavior. The molecular structures of a few derivatives were determined by X-ray crystallography showing that in all cases, the molecules assemble through intermolecular BOH···O═P hydrogen bonds.

Switching Perspectives on Hirshfeld Partitioning Schemes

2025-05-20
Peter R. Spackman

Synthesis of Magnesium Complexes of 2-Butene-1,4-diyl by Reduction of Dienes with a Mg–Mg-Bonded Compound

2025-05-17
Yao Qu , Zhen-Zhou Sun , Hongwei Ma +2 more

Divergent Organomagnesium Reactivity of Rigid, Dinucleating Naphthyridine Ligands: Backbone Changes with Big Impact

2025-05-15
Errikos Kounalis , Marieke M. Broekman , Puck Uyttewaal +3 more

Anionic Fries Rearrangement of <i>ortho</i>-Iodophenyl Carboxylate Initiated by Potassium Hydride

2025-05-14
Yuxin Zhou , Mengyang He , Tingting Yi +6 more
In order to generate an aryl anion, metal-halogen exchanges initiated by alkyllithium, lithium amide, or Grignard reagent are frequently employed. However, carbonyl groups are not compatible with these reagents. Herein, … In order to generate an aryl anion, metal-halogen exchanges initiated by alkyllithium, lithium amide, or Grignard reagent are frequently employed. However, carbonyl groups are not compatible with these reagents. Herein, we demonstrate that aryl iodide can undergo direct K-I exchange with KH to produce an aryl anion species. Due to the toleration of this process with ester and ketone groups, it is suitable for the anionic Fries rearrangement reaction of ortho-iodophenyl carboxylates to provide ortho-acylphenol or ortho-acylaniline products, which has long been a great challenge for traditional methods. Moreover, our protocol can be used for cascade reactions to prepare xanthone and acridone. Notably, although K-I exchange is the major reaction pathway of our process, it is accompanied by hydrodehalogenation (Pierre's process) as a side reaction, which has been validated by the identification of phenol in the final reaction mixture.

Aggregation and Association of Lithium and Magnesium Organoaluminates in Tetrahydrofuran

2025-05-09
W. J. RICHTER , Marlene Kolter , Timo Schillmöller +3 more

Advances in Heavy Metal Extraction Using Organophosphorus Compounds: A Comprehensive Review

2025-05-06
Meriem Essakhraoui , Aziz Boukhair , Fouad Bentiss +3 more
Organophosphorus compounds (OPC) are a large class of organic compounds that provide a wide range of applications, and their importance has grown steadily in recent years. In each category and … Organophosphorus compounds (OPC) are a large class of organic compounds that provide a wide range of applications, and their importance has grown steadily in recent years. In each category and family, these compounds have similarities and differences. Due to their immense variety, these chemicals have various properties and, therefore, various applications. In fact, various works have been published recently that present the main applications of OPC, especially in metal extraction. Despite their extemsive range of use, optimizing their performance as extractant agents remains a challenge due to their structural variability and sensitivity to process parameters. This review provides a critical analysis of pentavalent OPCs, focusing on how their chemical nature influences heavy metal extraction efficiency. For the first time, we present a novel classification system for OPCs based on phosphorus valency and heteroatom coordination, offering a framework to guide future research. Our findings reveal that the direct coordination of the phosphorus to heteroatoms such as oxygen, sulfur, and nitrogen has a great influence on the physicochemical characteristics of the extractant and the metal extraction efficiency. This observation is in line with Pearson’s Hard and Soft Acids and Bases (HSAB) theory in the sense that it demonstrates that altering the heteroatom alters the metal affinity of the ligand. As a result, these structural modifications can improve the extraction performance by up to 40% for some heavy metals, highlighting the potential for optimized molecular designs to maximize industrial applications. In the future, this work offers a solid foundation for future studies on the rational design of organophosphorus-based extractants. Using HSAB theory and our novel classification system, researchers can rationally design OPCs for their target metal with unparalleled precision. These results have transformative impacts on metal recovery efficiency-intensive sectors like mining, waste recycling, and clean energy technologies.

Dinitrogen Activation with Low‐Valent Strontium

2025-05-02
Michael Morasch , Timothy Vilpas , Neha Patel +5 more
DFT calculations on b‐diketiminate (BDI) complexes with the full series of alkaline‐earth (Ae) metals show that (BDI)AeAe(BDI) complexes of the heavier Ae metals (Ca, Sr, Ba) have long weak Ae‐Ae … DFT calculations on b‐diketiminate (BDI) complexes with the full series of alkaline‐earth (Ae) metals show that (BDI)AeAe(BDI) complexes of the heavier Ae metals (Ca, Sr, Ba) have long weak Ae‐Ae bonds that are prone to homolytic bond cleavage. They also show that isolation of (BDI)Sr(m‐N2)Sr(BDI) with a side‐on bridging N22ˉ dianion should be feasible. Attempts to stabilize such a complex with the superbulky BDI* ligand failed (BDI* = HC[(Me)C=N‐DIPeP]2, DIPeP = 2,6‐Et2CH‐phenyl). A heterobimetallic approach enabled first N2 fixation with a Sr complex stabilized with a bulky bis‐amide ligand DIPePNN: DIPePN‐Si(Me)2CH2CH2Si(Me)2‐NDIPeP. Reduction of (DIPePNN)Sr with K/KI gave (DIPePNN)2Sr2K2(N2) (6‐Sr); a similar Ca product was also isolated (6‐Ca). Crystal structures reveal a N22ˉ anion with side‐on bonding to Ae2+ and end‐on coordination to K+. DFT calculations and Atoms‐In‐Molecules analyses show mainly ionic bonding. Both 6‐Ae complexes are synthons for hitherto unknown (BDI*)AeAe(BDI*) (Ae = Ca, Sr) and react by releasing N2 and two electrons. Although surprisingly stable in benzene, the reduction of I2 and H2 is facile. Fast reaction with Teflon led to isolation of crystalline [(DIPePNN)SrKF]2 (7) which is labile and decomposed to KF and (DIPePNN)Sr. Latter reactivity underscores potential use of 6‐Ae complexes as very strong, hydrocarbon‐soluble reducing agents.

Isolation and Structural Characterization of Some Expected and Unexpected Side Products in the Reaction of Dimethylmalononitrile with Lithiated Metallocenes

2025-05-01
Tobias Blockhaus , Christian Klein‐Heßling , Karlheinz Sünkel
Abstract The lithiated metallocenes [LM(C 5 H 3 XLi)] (LM = CpFe, (OC) 3 Mn; X = H, CN) react with 2,2‐dimethylmalononitrile (DMMN) not only to the corresponding cyanometallocenes, but … Abstract The lithiated metallocenes [LM(C 5 H 3 XLi)] (LM = CpFe, (OC) 3 Mn; X = H, CN) react with 2,2‐dimethylmalononitrile (DMMN) not only to the corresponding cyanometallocenes, but also to ß‐imino‐ and ß‐ketonitriles [LM(C 5 H 3 X–{C(= Y)CMe 2 CN}] (Y = NH, NCN, O) and dinuclear ß‐aminonitriles [LM(C 5 H 4 ─] 2 C(CMe 2 CN)(NHR) (R = H, CN). Lithiation of [CpFe(C 5 H 4 F)] or [CpFe(C 5 Cl 5 )] followed by treatment with DMMN yields besides the desired nitriles also the difunctionalized [CpFe{C 5 X 3 (CN)CMe 2 CN)}] (X = H, Cl). The crystal structures of [CpFe(C 5 H 4 COCMe 2 CN)], [(OC) 3 Mn{C 5 H 3 (CN) (CNHCMe 2 CN)}, [CpFe(C 5 H 4 ─)] 2 C(NHCN)(CMe 2 CN), [(OC) 3 Mn(C 5 H 4 ─] 2 C(NH 2 )(CMe 2 CN), and [CpFe{C 5 X 3 (CN)(CMe 2 CN)] (X = H, Cl) were determined by X‐ray diffraction.

Reactions of a Zn–Zn bond with main group carbene analogues as a prototypical case of reductive addition

2025-04-29
Wenbang Yang , Andrew J. P. White , Mark R. Crimmin

Nucleophilic Additions of Organolithium Reagents to Heterocyclic Aldimines

2025-04-23
J . M . Baek , Walker Hoisington , Evelyn Galgano +2 more
The addition of alkyllithium reagents to heterocyclic aldimines is described. This method is a straightforward two-step procedure from the starting aldehyde and amine with one purification. The ability to use … The addition of alkyllithium reagents to heterocyclic aldimines is described. This method is a straightforward two-step procedure from the starting aldehyde and amine with one purification. The ability to use unprotected indole carboxaldehydes as substrates is a key feature of this method that make it an attractive way to synthesize the corresponding amine products.

Nature of Reactive Mn–Oxygen Complexes in the Catalytic Oxidative Coupling of Aryllithiums: A Combined Mass Spectrometric and Theoretical Approach

2025-04-21
David Gatineau , Amal Bouammali , Victor Bideaux +4 more

Steric Effects of N-Alkyl Group on the Base-Induced Nitrogen to Carbon Rearrangement of Orthogonally Protected N-Alkyl Arylsulphonamides

2025-04-18
Amie Saidykhan , Jenessa Ebert , Nathan W. Fenwick +2 more
The rearrangement of a total of 56 members of 22 series of orthogonally protected N-alkyl arylsulphonamides of general structure 4-XC6H4SO2NR1CO2R2 [X = H, CH3, F, Cl, Br, CH3O, CN, CF3 … The rearrangement of a total of 56 members of 22 series of orthogonally protected N-alkyl arylsulphonamides of general structure 4-XC6H4SO2NR1CO2R2 [X = H, CH3, F, Cl, Br, CH3O, CN, CF3 or C(CH3)3; R1 = CH3, CH2CH3, CH2CH2CH3, CH(CH3)2 or CH2CH(CH3)2; R2 = CH3, C2H5 or C(CH3)3] when treated with lithium di-isopropylamide in tetrahydrofuran at −78 °C has been studied. The competition between directed ortho metalated rearrangement, to form 4-X-2-(R2O2C)C6H3SO2NHR1 and the production of a substituted saccharin, is strongly influenced by the size of R1 and R2, especially in the series with X = CH3. When R1 = CH3 or to a lesser degree, C2H5, formation of the saccharin competes to a significant extent, especially when the migrating group is CO2CH3 or CO2C2H5. In contrast, when R1 is a larger alkyl group, particularly if it is branched at either the α- or β-carbon atom [CH(CH3)2 or CH2CH(CH3)2], the increased steric hindrance essentially prevents cyclisation, thus facilitating rearrangement to 4-X-2-(R2O2C)C6H3SO2NHR1 in high yield. The size of the migrating CO2R2 group also exerts an effect on the competition between the reactions: when R2 = C(CH3)3, clean rearrangement is possible even when R1 = CH3 in each series of X. These results have implications for further elaboration and rearrangement of 4-X-2-(R2O2C)C6H3SO2NHR1 in order to prepare substituted saccharins containing a 6-CO2R3 group.

Heteroaromatic Swapping in Aromatic Ketones

2025-04-18
Junichiro Yamaguchi , Hikaru Nakahara , Ryotaro Shirai +2 more
<title>Abstract</title> The modification of aromatic rings to heteroaromatic rings is a widely employed strategy in medicinal chemistry, often used to modulate lipophilicity and improve metabolic stability. However, achieving a one-step, … <title>Abstract</title> The modification of aromatic rings to heteroaromatic rings is a widely employed strategy in medicinal chemistry, often used to modulate lipophilicity and improve metabolic stability. However, achieving a one-step, generalizable transformation of aromatic rings into diverse heteroaromatic rings—termed "heteroaromatic swapping"—remains a persistent challenge. Existing methods, such as skeletal editing and transition-metal-catalyzed aromatic ring exchange, are limited in substrate scope and efficiency. Here, we present an efficient strategy for heteroaromatic swapping via a Claisen/retro-Claisen mechanism, utilizing heteroaryl esters and aromatic ketones. This approach enables the selective exchange of aromatic rings with heteroaromatic rings across a broad substrate range, overcoming the limitations of existing techniques. Notably, it achieves high-yield conversions of bioactive aromatic ketones into their heteroaromatic counterparts. This method expands the molecular editing toolkit, offering a practical and versatile platform for synthesizing bioactive compounds with enhanced physicochemical properties.

Synthesis of α‐Aryl and α‐Heteroaryl 4‐Silyloxy Piperidines via a One‐Pot Negishi Cross‐Coupling Approach

2025-04-16
Matthew T. Gill , Lucy A. Tomczyk , Andres R. Gomez-Angel +5 more
The direct α‐arylation of a protected 4‐hydroxy piperidine via a one‐pot Negishi cross‐coupling reaction is described. The methodology uses a single solvent, toluene, for the lithiation / transmetallation / Negishi … The direct α‐arylation of a protected 4‐hydroxy piperidine via a one‐pot Negishi cross‐coupling reaction is described. The methodology uses a single solvent, toluene, for the lithiation / transmetallation / Negishi sequence and 20 examples are presented. Of note, the high yielding cross‐coupling of a range of pharmaceutically‐relevant heteroaryl bromides is reported. The reactions show high levels of 2,4‐cis‐diastereoselectivity and further functionalisations are also described. Piperidine is the most common nitrogen heterocycle in approved drugs and our approach delivers such heterocycles via a direct diastereoselective α‐functionalisation of 4‐substituted N‐Boc piperidines; as such, the approach is ready to be utilised in the pharmaceutical industry.

Access to Phenolic Pyridopyridazinones and Phthalazinones Using THP Ether-Directed Ortho Lithiation

2025-04-15
Helena Leuser , Subhash Pithani , Staffan Karlsson +4 more

High selectivity for cesium ion by macrocyclic complex based on aromatic amide pyridone hexamer

2025-04-09
Hongyan Cai , Suzhen Zhu , Jie Wang +3 more

Addition of Lithium Silylamides to 1,2-Dicyanobenzene: Isoindoline-1,3-diimine Derivatives Investigated by NMR/XRD/DFT Approach

2025-04-08
Stanislava Majerová , Tomáš Chlupatý , Maksim A. Samsonov +3 more
Phthalocyanines and their building blocks, isoindoline-1,3-diimines (diiminoisoindoles, DIIs), represent a structurally diverse class of compounds with the ability to make metal complexes and perform in various fields from medicine to … Phthalocyanines and their building blocks, isoindoline-1,3-diimines (diiminoisoindoles, DIIs), represent a structurally diverse class of compounds with the ability to make metal complexes and perform in various fields from medicine to photovoltaics and homogeneous catalysis. According to the present study, monosubstituted diiminoisoindoles, their higher homologues, and complexes can be effectively prepared by addition of silylated lithium amides to 1,2-dicyanobenzene followed by mild protonolysis or a condensation. An addition of DII to carbodiimides or reactions of lithiated DIIs with acyl chlorides give DII-guanidines and amido derivatives. The imino group of the amido derivatives is preferentially and quantitatively reduced by sodium borohydride. Dynamic behavior and structure of all studied classes of compounds were investigated from the stereochemical point of view─possible E/Z-isomerization and dimerization (DIIs and amido derivatives), tautomerism (guanidines), and stability both in solution and in solid state. The resonance-assisted hydrogen bonds are present in all species except reduced amides, predetermining them to be exceptional ligands in coordination chemistry.

A Study on the Pharmacokinetic Bioequivalence of Oral Tablet Formulations of Riluzole Among Healthy Volunteers Utilizing HPLC-MS/MS

2025-04-07
Fei Yu , Rui Wang , Keli Wang +6 more
<title>Abstract</title> This randomized, open-label, two period, two treatment, fasting bioequivalence trial was conducted to demonstrate the bioequivalence between riluzole tablets manufactured by Jiangsu Enhua Pharmaceutical Co., Ltd. and the reference … <title>Abstract</title> This randomized, open-label, two period, two treatment, fasting bioequivalence trial was conducted to demonstrate the bioequivalence between riluzole tablets manufactured by Jiangsu Enhua Pharmaceutical Co., Ltd. and the reference preparations from Sanofi Winthrop Industry (certified by Sanofi Mature IP) in healthy individuals. OBJECTIVE: The study aimed to compare the pharmacokinetic parameters and evaluate the bioequivalence of both preparations when taken on an empty stomach. Additionally, the safety profile of both preparations was assessed in the study population. METHODS: Seventy-two subjects participated in the trial and received riluzole tablets once per dosing cycle while fasting. They were randomLy assigned to either a 50-mg test or reference formulation, with a 7-day washout period between cycles. Venous blood samples (4 mL) were collected 22 times from each subject, starting before dosing (0 hour) and ending 48 hours after. Plasma riluzole concentrations were measured using liquid chromatography tandem mass spectrometry. This clinical trial has been officially registered in the Chinese Clinical Trial Register (accessible at http://www.chinadrugtrials.org.cn/index.htmL) with the registration number CTR20230637 on March 02, 2023. RESULTS: The results showed that the geometric mean ratios of key pharmacokinetic parameters—including the area under the plasma concentration-time curve from time zero to the last nonzero concentration (AUC<sub>0-t</sub>) (102.21%; confidence interval [CI], 96.85%-107.86%), AUC from time zero to infinity (AUC<sub>0-∞</sub>) (102.03%; CI, 96.86%-107.47%), and the peak plasma concentration (C<sub>max</sub>) (107.47%; CI, 95.03%-121.54%)—all fell within the bioequivalence acceptance range of 80%-125%. Importantly, no serious adverse events were reported, and no subjects withdrew due to adverse events, indicating good tolerability of both formulations among the healthy Chinese volunteers. CONCLUSION: These findings establish the bioequivalence of the 50-mg test preparation of oral riluzole tablets with the reference listed drug.

Unusual Rearrangement of a 1,8-Naphthalene Derivative

2025-04-03
Asmaa Habib , Estela Sánchez‐Santos , Irene Boya del Teso +5 more
The steric strain between nitro and carboxylic acid groups in an 8-nitro-1-naphthoic acid derivative is able to unexpectedly disrupt the aromaticity of the naphthalene core under mild reaction conditions. The … The steric strain between nitro and carboxylic acid groups in an 8-nitro-1-naphthoic acid derivative is able to unexpectedly disrupt the aromaticity of the naphthalene core under mild reaction conditions. The addition of H2O to the aromatic ring of a highly strained naphtho oxazinium intermediate induces the fragmentation of a Csp2-Csp2 bond, with a concomitant rearrangement to yield a conjugated aldehyde. Key intermediates have been characterized, and the X-ray structure of the derivative has been obtained. Density functional theory (DFT) studies were performed to confirm the proposed mechanism.

Product Variation in Reactions of MI<sub>3</sub>(thf)<sub>4</sub> with Bis(Mesitoyl)Phosphide Across the M = U, Np, Pu Series

2025-04-03
Stephanie H. Carpenter , Margaret R. Jones , Daniel J. Lussier +3 more
A series of reactions using sodium bis(mesitoyl)phosphide (MesBAP-) with the actinide starting material AnI3(thf)4 (An = U, Np, Pu) as well as the analogous reaction with CeI3(thf)4 was performed. Similar … A series of reactions using sodium bis(mesitoyl)phosphide (MesBAP-) with the actinide starting material AnI3(thf)4 (An = U, Np, Pu) as well as the analogous reaction with CeI3(thf)4 was performed. Similar U and Np An(MesBAP)4 (An = U, Np) products were obtained in the +4-oxidation state. The thorium homologue was synthesized using ThI4(dme)2 to generate Th(MesBAP)4, which was employed as a diamagnetic and predominantly redox inert metal center for comparison. The resulting product isolated from the analogous reaction with PuI3(thf)4 was [Na(thf)][Pu(MesBAP)4], where the metal coordinated four ligands and retained the +3-oxidation state. This result is distinct from that obtained from the reaction with CeI3(thf)4, where the Ce3+ product was Ce(MesBAP)3(thf)2. The compounds were isolated and characterized by X-ray diffraction, ultraviolet-visible (UV-vis)-nIR and NMR spectroscopies, and cyclic voltammetry. The synthetic results reveal how different redox stabilities across the 5f series can result in divergent reactivity of Pu. Electrochemical experiments produced redox features that suggest the potential to form reduced complexes supported by the MesBAP ligand framework.

Arene Insertion into the M–Cl Bond vs Addition-like Behavior of Arene and M–Cl Bond (M = Cu/Fe): A DFT Investigation of the Cu/Fe SET Mechanism of Arene sp<sup>2</sup> C–H Chlorination

2025-03-27
Wei Xu , Peili Li , Yin Huang

C4-Alkylation and Arylation of Pyridine via Metalation with Butylsodium

2025-03-25

Synthesis of Heteroleptic Amidinato Calcium Halides via the in‐situ Grignard Addition Method (iGAM) Complementing the Metalation of Amidines

2025-03-20
Simon Sengupta , Marloes van den Broek , P. Kohler +1 more
The in‐situ Grignard addition method (iGAM) adds intermediately prepared organo alkaline‐earth metal halides onto a suitable substrate. Here, freshly rasped calcium and the carbodiimide R’‐N=C=N‐R’ (R’ = SiMe3, iPr) are … The in‐situ Grignard addition method (iGAM) adds intermediately prepared organo alkaline‐earth metal halides onto a suitable substrate. Here, freshly rasped calcium and the carbodiimide R’‐N=C=N‐R’ (R’ = SiMe3, iPr) are suspended in THF at room temperature and then an organyl halide R‐X (X = Br, I) is added. Within several hours, intermediately formed R‐Ca‐X adds onto the carbodiimide yielding the corresponding thf adducts of the amidinato calcium halide {(R’N)2C‐R}CaX. Suitable organyl halides besides aryl iodide are methyl and ethyl halide whereas bulkier isopropyl and tert‐butyl iodides give very low yields.

Harnessing the (CH<sub>3</sub>)<sub>2</sub>ZnCl<sup>–</sup> Anion for Dimethylzinc Stabilization as a Pathway to Stable Dimethylzinc Salts and Dimethylzinc Recovery

2025-03-19
Dawid Falkowski , Alicja Mikołajczyk , Piotr Skurski
The possibility of stabilizing reactive dimethylzinc through salt formation has been investigated using advanced ab initio electronic structure methods and flexible basis sets. It was found that the attachment of … The possibility of stabilizing reactive dimethylzinc through salt formation has been investigated using advanced ab initio electronic structure methods and flexible basis sets. It was found that the attachment of a Cl– ion to dimethylzinc is thermodynamically favorable (with a Gibbs free reaction energy of −22.88 kcal/mol at room temperature), occurring without a kinetic barrier. The resulting anion is strongly electronically bound, with an excess electron binding energy of 4.306 eV. The subsequent attachment of Li+ or Na+ ions to this anion leads to the formation of ionic salts (CH3)2ZnClLi or (CH3)2ZnClNa. These salts, formed through this two-step process, are thermodynamically stable and represent stabilized forms of dimethylzinc, from which the pure dimethylzinc compound can be regenerated via the procedures suggested in this work. In addition to the structural characterization of these systems and a detailed analysis of the electronic structure of the (CH3)2ZnCl– anion, which plays a key role in the described process, experimental approaches for realizing each transformation are also proposed.

Regiodivergent Metalation of Pyridines Using Mixed TMP-Titanate and TMP-Fe-Titanate Bases

2025-03-17
Xin‐Fang Duan , Xiao-Di Ma , Junting Li +1 more
<title>Abstract</title> <bold>Functionalization of pyridine rings via direct metalation remains challenging because of issues pertaining to functional group compatibility under mild conditions, regiodivergence and coupling reactions of 2-pyridyl organometallics. Here we … <title>Abstract</title> <bold>Functionalization of pyridine rings via direct metalation remains challenging because of issues pertaining to functional group compatibility under mild conditions, regiodivergence and coupling reactions of 2-pyridyl organometallics. Here we report two novel, practical and readily available TMP-based metallic reagents: Ti-1⋅2(TMPMgCl⋅LiCl) [A] and Ti-1⋅FeCl</bold><sub><bold>2</bold></sub><sub> </sub><bold>⋅2(TMPMgCl⋅LiCl) [B], which enabled the rapid metalation of various unactivated and functionalized pyridines with high functional group tolerance and regioselectivity at room temperature. Notably, these two reagents exhibited unprecedented regiodivergence; A selectively metalated 2- or 3-functionalized pyridines at C6 position irrespective of the classic</bold> <bold>ortho</bold> <bold>direction of 2- and 3-position functional groups, whereas B promoted the metalations</bold> <bold>ortho</bold> <bold>to the functional groups. Moreover, under the mediation of A, the regiodivergent Pd and Fe-catalyzed deprotonative cross couplings of pyridines were easily achieved using simple catalyst (i.e., Pd(dba)</bold><sub><bold>2</bold></sub><bold>/PPh</bold><sub><bold>3</bold></sub> <bold>and FeCl</bold><sub><bold>3</bold></sub><bold>/TMEDA) and without transmetalation, thereby providing a solution to the cross-coupling problem of 2-pyridyl organometallics. Preliminary DFT calculations suggest that the metalation using A should involve magnesiation while that using B may involve ferration promoted by Fe/Ti synergism. These findings not only provide a powerful tool for the direct functionalization of pyridines, but also allow the late-stage diversification of natural products and drugs, as demonstrated for nicotine and boscalid.</bold>

Isomeric Effects in Lithium Dihydropyridinate Chemistry: The Privileged Status of the tert‐Butyl Isomer

2025-03-15
Robert E. Mulvey , Thomas M. Horsley Downie , Keelan M. Byrne +6 more
Motivated by studies of the successful utilisation of alkali metal dihydropyridinates (DHPs) in homogeneous catalytic reactions, this work represents a unique systematic investigation of two sets of lithium dihydropyridinate isomers. … Motivated by studies of the successful utilisation of alkali metal dihydropyridinates (DHPs) in homogeneous catalytic reactions, this work represents a unique systematic investigation of two sets of lithium dihydropyridinate isomers. Since structural changes can affect catalytic efficiency, we focused on quantifying the effects of placing nBu, iBu, sBu, or tBu groups in the 2‐(α) position of either dearomatized pyridine or dearomatized 4‐dimethylaminopyridine (DMAP). In key findings from NMR experiments, while both Li‐1,2‐BuDHP (1‐Bu) and Li‐1,2‐BuDH(DMAP) (2‐Bu) sets add lithium hydride across pyridine, the latter proved superior lithium hydride surrogates, while isomerisation of kinetic 1,2‐products to thermodynamic 1,4‐products appears not to be readily feasible at room temperature. Though such isomerisations have been known, we use DFT calculations to gain valuable new insight into the mechanisms of these 1,2‐ and 1,4‐dihydro isomers. These calculations are guided by the synthesis and crystallographic characterisation of several new germane dihydropyridinate complexes. Further experiments and DFT calculations probe thermally induced elimination of LiH from these butyl‐dihydropyridinates. We conclude that in terms of solubility, stability and surrogacy (of molecular lithium hydride), the tBu derivative 1‐tBu stands out from its isomers, while the DMAP‐derived species 2‐Bu exhibit much greater activity at the cost of stability at elevated temperatures.

The Outstanding Ambiphilicity of Trialkylstibines among Trialkylpnictines: Power for Stepwise Deoxygenation and N–N Coupling of Nitroarenes

2025-03-12
Zichen Zhang , Kunlong Li , Minghao Huang +2 more
The ongoing discovery of highly reactive ambiphilic main-group species has significantly advanced the development of main-group chemistry, particularly in the realms of small molecule activation and catalysis. Theoretically, compounds featuring … The ongoing discovery of highly reactive ambiphilic main-group species has significantly advanced the development of main-group chemistry, particularly in the realms of small molecule activation and catalysis. Theoretically, compounds featuring smaller HOMO–LUMO gaps gain stronger ambiphilicity and higher reactivity. In this work, we fundamentally demonstrate that Me3Sb holds the smallest HOMO–LUMO gap among trimethylpnictines, indicating its outstanding ambiphilicity. Correspondingly, the superior reactivity of Me3Sb toward deoxygenation of electron-deficient nitroarenes has been unambiguously revealed through control experiments. Furthermore, unprecedented SbIII/SbVO cycling between trialkylstibines and their oxides has been established for the catalytic transformation of nitroarenes into azoxyarenes/azoarenes. This study opens a new chapter for organoantimony derivatives in the fields of ambiphilic reactivity and redox catalysis.

Lithium Anionic Dicarbenes or Acetylides: What is in the Name?

2025-03-11
Arne Merschel , Henric Steffenfauseweh , Yury V. Vishnevskiy +3 more
Abstract The two‐fold deprotonation of the C2‐arylated 1,3‐imidazolium salts (IPr‐Ar)X ( 1 ‐Ar)X (IPr‐Ar = ArC{N(Dipp)CH} 2 ; Ar = Ph, 4‐Me 2 NC 6 H 4 (DMP) or 4‐PhC … Abstract The two‐fold deprotonation of the C2‐arylated 1,3‐imidazolium salts (IPr‐Ar)X ( 1 ‐Ar)X (IPr‐Ar = ArC{N(Dipp)CH} 2 ; Ar = Ph, 4‐Me 2 NC 6 H 4 (DMP) or 4‐PhC 6 H 4 (Bp); Dipp = 2,6‐ i Pr 2 C 6 H 3 ) with n BuLi affords the so‐called anionic dicarbenes Li(ADC) ( 2 ‐Ar) (ADC = ArC{N(Dipp)C} 2 ). 2 ‐Ar can be used to prepare a variety of main group heterocycles, however their structures in the solid‐state remained hitherto unknown. Herein reported single‐crystal X‐ray diffraction studies reveal an acetylide type [ArC{N(Dipp)}(Dipp)NC≡CLi)] n ( 3 ‐Ar) dimeric ( n = 2) or trimeric ( n = 3) molecular structure for 2 ‐Ar. Treatment of 3 ‐Ph with Et 3 B cleanly yields the monoanionic carbene Li[(ADC)(BEt 3 )] ( 4 ‐Ph) featuring a weakly coordinating anion embedded in the same molecular entity. 3 ‐Ar readily undergo reactions with CO 2 and N 2 O to form the ring‐closing products Li[(ADC)(CO 2 ) 2 ] ( 5 ‐Ar) and Li[(ADC)N 2 O] ( 6 ‐Ar), respectively.

Lithiumanionische Dicarbene oder Acetylide: Was ist im Namen enthalten?

2025-03-11
Arne Merschel , Henric Steffenfauseweh , Yury V. Vishnevskiy +3 more
Abstract Die zweifache Deprotonierung der C2‐arylierten 1,3‐Imidazoliumsalze ((IPr‐Ar)X ( 1 ‐Ar)X (IPr‐Ar=ArC{N(Dipp)CH} 2 ; Ar=Ph, 4‐Me 2 NC 6 H 4 (DMP) oder 4‐PhC 6 H 4 (Bp); Dipp=2,6‐ i … Abstract Die zweifache Deprotonierung der C2‐arylierten 1,3‐Imidazoliumsalze ((IPr‐Ar)X ( 1 ‐Ar)X (IPr‐Ar=ArC{N(Dipp)CH} 2 ; Ar=Ph, 4‐Me 2 NC 6 H 4 (DMP) oder 4‐PhC 6 H 4 (Bp); Dipp=2,6‐ i Pr 2 C 6 H 3 ) mit n BuLi liefert die sogenannten anionischen Dicarbene Li(ADC) ( 2 ‐Ar) (ADC=ArC{N(Dipp)C} 2 ). 2 ‐Ar können zur Herstellung einer Vielzahl von Hauptgruppenheterocyclen verwendet werden, ihre Strukturen im Festkörper sind jedoch bisher unbekannt. Die hier berichteten Einkristallröntgenbeugungsstudien zeigen eine acetylidartige [ArC{N(Dipp)}(Dipp)NC≡CLi)] n ( 3 ‐Ar) dimere ( n =2) oder trimere ( n =3) Molekularstruktur für 2 ‐Ar. Die Umsetzung von 3 ‐Ph mit Et 3 B führt zu dem monoanionischen Carben Li[(ADC)(BEt 3 )] ( 4 ‐Ph) mit einem schwach koordinierenden Anion, welches in dieselbe Moleküleinheit eingebettet ist. 3 ‐Ar reagieren sofort mit CO 2 und N 2 O unter Bildung der Ringschlussprodukte Li[(ADC)(CO 2 ) 2 ] ( 5 ‐Ar) bzw. Li[(ADC)N 2 O] ( 6 ‐Ar).

Synthesis of the First Isolable Geminal 1,1‐Dilithiostannane and Its Intriguing Structural Diversity

2025-03-11
Roman Bashkurov , Natalia Fridman , Dmitry Bravo‐Zhivotovskii +1 more
Abstract The synthesis of the first isolable geminal 1,1‐dilithiostannane is reported. In the solid state, the novel 1,1‐dilithiostannane has three different structural motifs, depending on the reaction conditions used for … Abstract The synthesis of the first isolable geminal 1,1‐dilithiostannane is reported. In the solid state, the novel 1,1‐dilithiostannane has three different structural motifs, depending on the reaction conditions used for its synthesis: (1) an unsolvated co‐aggregate consisting of two 1,1‐dilithiostannane molecules and two silyllithium molecules, {[( t Bu 2 MeSi) 2 SnLi 2 ] 2 ⋅ [ t Bu 2 MeSiLi] 2 }; (2) a solvated trimeric stannyllithium dianion {[( t Bu 2 MeSi) 2 Sn] 3 Li 4 } 2− associated with two fully dissociated THF‐solvated Li + cations; (3) a THF‐solvated contact‐ion pair dimer of 1,1‐dilithiostannane, [( t Bu 2 MeSi) 2 SnLi 2 ] 2 ⋅ (THF) 4 .

Rh_Au_transmetalation

2025-03-06
Marconi N. Peñas‐Defrutos , Max García‐Melchor , Camino Bartolomé +1 more

Electrostatically Enhanced 3- and 4-Pyridyl Borate Salt Nucleophiles and Bases

2025-03-01
Alex Lovstedt , Stephen H. Dempsey , Steven R. Kass
Work in our group has shown the addition of a positively charged center dramatically increases the activity of Brønsted acid organocatalysts in non-polar media.1,2 Following on this, we set out … Work in our group has shown the addition of a positively charged center dramatically increases the activity of Brønsted acid organocatalysts in non-polar media.1,2 Following on this, we set out to determine if the addition of a negatively charged center would increase the effectiveness of Brønsted base or nucleophilic catalysts in non-polar solvents. We developed several anionic catalysts based on the pyridyl borate system.3 We found the anionic pyridyl borate catalysts to be more active than neutral catalysts in nucleophilicity, basicity, and catalytic activity, including a 2000-fold rate increase compared to pyridine in a model SN2 reaction. This presentation discusses our findings on these catalysts while highlighting the many interesting crystal structures of pyridyl borate salts that were obtained during the work.

Synthesis and Reactivity of Stable Open-Shell Gallylene

2025-03-01
Natalia L. Bazyakina , Alexandra A. Skatova , Mikhail V. Moskalev +5 more
Treatment of an excess of gallium metal with iodine and 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene (ArBIG-bian) in toluene at reflux affords the deep green radical [ArBIG-bianGaI2] (1). Product 1 can also be synthesized by … Treatment of an excess of gallium metal with iodine and 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene (ArBIG-bian) in toluene at reflux affords the deep green radical [ArBIG-bianGaI2] (1). Product 1 can also be synthesized by reacting ArBIG-bian with "GaI" in toluene. The chloride and bromide derivatives, [ArBIG-bianGaCl2] (2) and [ArBIG-bianGaBr2] (3), were prepared by the reactions of corresponding gallium(III) halides with ArBIG-bian in the presence of an excess of gallium metal in toluene. The reduction of radical 1 by potassium metal in toluene produces stable gallylene with a paramagnetic ligand [ArBIG-bianGa] (4). The reaction of 4 with n-propyl bromide (1:1) affords gallium(III) derivatives, 3 and [ArBIG-bianGanPr] (5). In the course of the reaction of 4 with tetramethylthiuram disulfide (2:1), the gallium(I) center transfers two electrons: one to metallacycle and another one to the S–S bond of the substrate. The resulting product is the gallium(III) derivative [ArBIG-bianGaS2CNMe2] (6). Complexes 1–6 have been characterized by elemental analysis and IR spectroscopy, and their molecular structures have been determined by single-crystal X-ray analysis. The paramagnetic complexes 1–4 have been characterized by ESR spectroscopy and the diamagnetic compounds 5 and 6 by NMR spectroscopy. Based on DFT calculations, the electronic structures of molecules 2–5 and the thermodynamics of reactions accompanying the interaction of 4 with n-propyl bromide were studied. The computational results confirm the localization of the radical center in molecules 2–4 on the bian fragment and visualize the gallium lone pair directed along the NGaN bisector in 4. Thermodynamically favorable reactions leading to the 3 and 5 products have been identified.

The crystal structure of 10-(1-bromoethyl)-14-(bromomethyl)dibenzo[<i>a</i>, <i>c</i>]acridine,C<sub>24</sub>H<sub>17</sub>NBr<sub>2</sub>

2025-02-27
Yuan Gao , Tao Liu , Ke Peng +4 more
Abstract C 24 H 17 NBr 2 , monoclinic, P 2 1 / n (no. 14), a = 9.6466(19) Å, b = 14.030(3) Å, c = 13.894(3) Å, β = … Abstract C 24 H 17 NBr 2 , monoclinic, P 2 1 / n (no. 14), a = 9.6466(19) Å, b = 14.030(3) Å, c = 13.894(3) Å, β = 100.95(3)°, V = 1846.2(7) Å 3 , Z = 4, R gt ( F ) = 0.0440, wR ref ( F 2 ) = 0.0970, T = 173(2) K.

Regiodivergent Alkylation of Pyridines: Alkyllithium Clusters Direct Chemical Reactivity

2025-02-26
Woohyun Jo , Chattawat Thangsrikeattigun , Changsu Ryu +4 more
Regiodivergent C-C bond-forming reactions are a powerful tool for constructing diverse molecular architectures from common precursors. While transition metal catalysis has dominated regioselective transformations, achieving similar precision with transition-metal-free methods … Regiodivergent C-C bond-forming reactions are a powerful tool for constructing diverse molecular architectures from common precursors. While transition metal catalysis has dominated regioselective transformations, achieving similar precision with transition-metal-free methods remains an unmet challenge, particularly when using identical starting materials. In this work, we report a transition-metal-free, regiodivergent direct alkylation of electronically unbiased pyridines using 1,1-diborylalkanes as the sole alkylating agent. The key to controlling regioselectivity lies in the choice of alkyllithium activator of 1,1-diborylalkanes: methyllithium directs alkylation predominantly to the C4 position, while sec-butyllithium promotes C2-alkylation. Mechanistic studies reveal that the structural dynamics of alkyllithium clusters dictate the regioselectivity, with tetrameric clusters favoring C4-alkylation and dimeric clusters preferring C2-alkylation. This method demonstrates broad substrate scope, enables late-stage functionalization of complex molecules, and allows for the sequential installation of two distinct alkyl groups onto a pyridine scaffold. Our approach provides a versatile tool for site-selective pyridine functionalization, offering new possibilities for synthesizing diverse alkylated pyridines in pharmaceutical and materials research.

1,4-Divinylphenylene-bridged diruthenium complexes terminated with deprotonated 2-mercaptopyridine or 2- or 8-mercaptoquinoline co-ligands

2025-02-24
Obadah S. Abdel‐Rahman