Cobalt-Catalyzed Sequential Site- and Stereoselective Hydrosilylation of 1,3- and 1,4-Enynes

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(12), P. 5233 - 5240

Published: March 17, 2022

Catalytic sequential hydrosilylation of 1,3-enynes and 1,4-enynes promoted by cobalt complexes derived from bisphosphines are presented. Site- stereoselective Si–H addition primary silanes to followed intramolecular diastereo- enantioselective afforded enantioenriched cyclic alkenylsilanes with simultaneous construction a carbon-stereogenic center silicon-stereogenic center. Reactions proceeded through isomerization the alkene moiety site- hydrosilylation. A wide range were in high efficiency selectivity. Functionalization containing stereogenic at silicon delivered variety chiral building blocks that otherwise difficult access.

Language: Английский

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Synthesis of Cyclopropenols Enabled by Visible‐Light‐Induced Organocatalyzed [2+1] Cyclization

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(10)

Published: Jan. 7, 2022

Although the synthesis of common cyclopropenes has been well studied, access to cyclopropenols is rather limited. Herein, we report first α-trifluoromethylated via 2+1 cycloaddition reactions between alkynes and trifluoroacylsilanes, enabled by visible-light-induced organocatalysis. The novel ambiphilic donor-acceptor carbenes derived from trifluoroacetylsilanes reacted efficiently with both activated non-activated alkynes. reaction features simple operation, mild conditions, broad substrate scope good functional group tolerance. synthetic potential highlighted gram-scale cyclopropanols through combination cyclization high diastereoselective hydrogenation in one pot.

Language: Английский

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Enantioselective Hydrothiolation: Diverging Cyclopropenes through Ligand Control

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(16), P. 6176 - 6184

Published: April 15, 2021

In this article, we advance Rh-catalyzed hydrothiolation through the divergent reactivity of cyclopropenes. Cyclopropenes undergo to provide cyclopropyl sulfides or allylic sulfides. The choice bisphosphine ligand dictates whether pathway involves ring-retention ring-opening. Mechanistic studies reveal origin for switchable selectivity. Our results suggest two pathways share a common cyclopropyl-Rh(III) intermediate. Electron-rich Josiphos ligands promote direct reductive elimination from intermediate afford in high enantio- and diastereoselectivities. Alternatively, atropisomeric (such as DTBM-BINAP) enable ring-opening generate with regiocontrol.

Language: Английский

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Cobalt-Catalyzed Diastereo- and Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(32), P. 12755 - 12765

Published: Aug. 5, 2021

Catalytic generation of ambiphilic π-allyl–metal complexes and their utility in enantioselective transformations constitutes a powerful approach for introduction allyl groups to molecule. Herein an unprecedented cobalt-catalyzed highly site-, diastereo-, protocol stereoselective formation nucleophilic allyl–Co(II) followed by addition aldehydes is presented. The reaction features diastereo- enantioconvergent conversion easily accessible allylic alcohol derivatives diversified enantioenriched homoallylic alcohols with remarkably broad scope that can be introduced. Mechanistic studies indicated radical intermediates were involved this process. These new discoveries establish strategy development through capture radicals chiral Co complexes, pushing forward the frontier catalysis.

Language: Английский

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Cobalt‐Catalyzed Chemo‐ and Enantioselective Hydrogenation of Conjugated Enynes

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(31), P. 16989 - 16993

Published: June 1, 2021

Asymmetric hydrogenation is one of the most powerful methods for preparation single enantiomer compounds. However, chemo- and enantioselective relatively inert unsaturated group in substrates possessing multiple bonds remains a challenge. We herein report protocol highly conjugated enynes while keeping alkynyl bond intact. Mechanism studies indicate that accompanying Zn2+ generated from zinc reduction CoII complex plays critical role to initiate plausible CoI /CoIII catalytic cycle. This approach allows efficient generation chiral propargylamines (up 99.9 % ee 2000 S/C) further useful chemical transformations.

Language: Английский

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Nickel‐Catalyzed Asymmetric Hydroaryloxy‐ and Hydroalkoxycarbonylation of Cyclopropenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(36)

Published: July 15, 2022

Abstract The asymmetric Reppe carbonylation reactions provide a straightforward access to α ‐chiral carbonyl compounds. reported paradigms predominantly adopted precious palladium as the catalyst. Here we report nickel‐catalyzed of cyclopropenes with phenyl formate and CO/ROH, respectively. This asymmetrical synthetic protocol features high atom economy, good functional group tolerance, which rapidly constructs polysubstituted cyclopropanecarboxylic derivatives excellent diastereo‐ enantioselectivity. utility is demonstrated by facile conversion chiral products into bioactive molecules such (−)‐Tranylcypromine (−)‐Lemborexant.

Language: Английский

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Cobalt‐Catalyzed Regio‐, Diastereo‐ and Enantioselective Intermolecular Hydrosilylation of 1,3‐Dienes with Prochiral Silanes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(30)

Published: May 24, 2022

Abstract One of the most straightforward approaches to access chiral silanes is catalytic enantioselective hydrosilylation. Although significant advances have been achieved in construction either a carbon‐stereogenic center or silicon‐stereogenic through hydrosilylation, simultaneous establishment carbon‐ and an acyclic molecule single intermolecular hydrosilylation remained undeveloped. Herein, unprecedented cobalt‐catalyzed regio‐, diastereo‐ 1,3‐dienes presented, enabling transformation. A wide range bearing were generated high efficiency stereoselectivity. Functionalization enantioenriched delivered variety valuable building blocks that are otherwise difficult access.

Language: Английский

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Nickel‐Hydride‐Catalyzed Diastereo‐ and Enantioselective Hydroalkylation of Cyclopropenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(46)

Published: Sept. 20, 2022

Abstract Cyclopropanes are structural motifs that widely present in natural products and bioactive molecules, they also tremendously useful building blocks synthetic organic chemistry. Asymmetric synthesis of cyclopropane derivatives has been an intensively researched area over the years, but efficient asymmetric preparation alkylcyclopropane scaffolds remains a challenging topic. Herein, we report nickel‐hydride‐catalyzed enantioselective diastereoselective hydroalkylation cyclopropenes for facile chiral motifs. The reported method is versatile, taking place under mild reaction conditions, having broad applicability excellent functional group tolerance.

Language: Английский

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Catalytic desymmetrization reactions to synthesize all-carbon quaternary stereocentres

Nature Synthesis, Journal Year: 2023, Volume and Issue: 2(11), P. 1020 - 1036

Published: Oct. 16, 2023

Language: Английский

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Cobalt-Catalyzed Diastereo- and Enantioselective Carbon–Carbon Bond Forming Reactions of Cyclobutenes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(6), P. 3588 - 3598

Published: Feb. 3, 2023

Catalytic enantioselective functionalization of cyclobutenes constitutes a general and modular strategy for construction enantioenriched complex cyclobutanes bearing multiple stereogenic centers, as chiral four-membered rings are common motifs in biologically active molecules versatile intermediates organic synthesis. However, synthesis through such remained significantly limited. Herein, we report series unprecedented cobalt-catalyzed carbon-carbon bond forming reactions that initiated carbometalation. The protocols feature diastereo- introduction allyl, alkynyl, functionalized alkyl groups. Mechanistic studies indicated an unusual 1,3-cobalt migration subsequent β-carbon elimination cascade process occurred the allyl addition. These new discoveries established elementary cobalt catalysis extension diversity nucleophiles transformations cyclobutenes.

Language: Английский

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