Chiral Cyclopentadienyl Ligands: Design, Syntheses, and Applications in Asymmetric Catalysis

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(24), P. 13198 - 13224

Published: July 16, 2020

The creation of new chiral ligands capable providing high stereocontrol in metal-catalyzed reactions is crucial modern organic synthesis. production bioactive molecules as single enantiomers increasingly required, and asymmetric catalysis with metal complexes constitutes one the most efficient synthetic strategies to access optically active compounds. Herein we offer a historical overview on development derivatives ubiquitous cyclopentadienyl ligand (CpX ), detail their successful application broad range transformations. Those include functionalization challenging C-H bonds beyond, giving an extensive catalogue valuable molecules. A critical comparison existing families, design, synthesis, complexation different metals also provided. In addition, future research directions are discussed further enhance performance CpX enantioselective catalysis.

Language: Английский

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Rhodium-Catalyzed Asymmetric C–H Functionalization Reactions

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(16), P. 10079 - 10134

Published: Aug. 1, 2023

This review summarizes the advancements in rhodium-catalyzed asymmetric C–H functionalization reactions during last two decades. Parallel to rapidly developed palladium catalysis, rhodium catalysis has attracted extensive attention because of its unique reactivity and selectivity reactions. In recent years, Rh-catalyzed have been significantly many respects, including catalyst design, reaction development, mechanistic investigation, application synthesis complex functional molecules. presents an explicit outline catalysts ligands, mechanism, scope coupling reagents, applications.

Language: Английский

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Dispersion and Steric Effects on Enantio-/Diastereoselectivities in Synergistic Dual Transition-Metal Catalysis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(4), P. 1971 - 1985

Published: Jan. 20, 2022

Comprehensive computational studies were carried out to explore the mechanisms of enantioselective Cu/Pd and stereodivergent Cu/Ir dual-catalytic syntheses α,α-disubstituted α-amino acids (α-AAs). A chiral copper azomethine ylide undergoes facile α-allylation with racemic π-allylpalladium species or stereopure π-allyliridium complex stereoconvergently stereodivergently furnish single/double stereocenters, respectively. Stereoselectivity at α-center is controlled by facial selectivity respect prochiral nucleophile. Despite apparently similar transition-state assemblies, models distortion/interaction analyses disclose versatile modes stereoinduction wherein can face-selectively intercept metal−π-allyl intermediates utilizing attractive dispersion interactions and/or sterically caused distortions. Generation β-stereocenter in system relies on a stereospecifically generated allyliridium electronically branched-to-linear selectivity, while dual yields linear monochiral product due steric factors π–π stacking interactions. The demonstrate molecular level how ligand-encoded information transferred α-/β-sites resulting α-AAs mode regio-/stereoselection altered differences transition-metal-stabilized coupling partners. To facilitate stereoselective catalysis, suite analytical tools extract controlling for asymmetric induction demonstrated.

Language: Английский

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Rhodium(III)‐Catalyzed Atroposelective Synthesis of Biaryls by C−H Activation and Intermolecular Coupling with Sterically Hindered Alkynes

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(32), P. 13288 - 13294

Published: April 16, 2020

Abstract Reported herein is the atroposelective synthesis of biaryl NH isoquinolones by Rh III ‐catalyzed C−H activation benzamides and intermolecular [4+2] annulation for a broad scope 2‐substituted 1‐alkynylnaphthalenes, as well sterically hindered, symmetric diarylacetylenes. The axial chirality constructed based on dynamic kinetic transformation alkyne in redox‐neutral with benzamides, insertion being stereodetermining. reaction accommodates both heteroaryl carboxamides proceeds excellent regioselectivity (if applicable) enantioselectivities (average 91.8 % ee ). An enantiomerically diastereomerically pure rhodacyclic complex was prepared offers insight into enantiomeric control coupling system, wherein steric interactions between amide directing group substrate dictate regio‐ enantioselectivity.

Language: Английский

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Oxygen‐Linked Cyclopentadienyl Rhodium(III) Complexes‐Catalyzed Asymmetric C−H Arylation of Benzo[h]quinolines with 1‐Diazonaphthoquinones

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(28), P. 15510 - 15516

Published: April 16, 2021

Abstract Chiral cyclopentadienyl rhodium (CpRh) complex‐catalyzed asymmetric C−H functionalization reactions have witnessed a significant progress in organic synthesis. In sharp contrast, the reported chiral Cp ligands are limited to C‐linked and often synthetically challenging. To address these issues, we developed novel class of tunable bearing oxygen linkers, which were efficient catalysts for arylation benzo[ h ]quinolines with 1‐diazonaphthoquinones, affording axially heterobiaryls excellent yields enantioselectivity (up 99 % yield, 98.5:1.5 er). Mechanistic studies suggest that reaction is likely proceed by electrophilic activation, followed coupling cyclometalated rhodium(III) complex 1‐diazonaphthoquinones.

Language: Английский

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Rhodium‐Catalyzed C−H Activation‐Based Construction of Axially and Centrally Chiral Indenes through Two Discrete Insertions

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(30), P. 16628 - 16633

Published: May 19, 2021

Abstract Reported herein is asymmetric [3+2] annulation of arylnitrones with different classes alkynes catalyzed by chiral rhodium(III) complexes, the nitrone acting as an electrophilic directing group. Three indenes/indenones have been effectively constructed, depending on nature substrates. The coupling system features mild reaction conditions, excellent enantioselectivity, and high atom‐economy. In particular, N ‐benzylnitrones sterically hindered afforded C−C or C−N atropochiral pentatomic biaryls a C‐centered point‐chirality in enantio‐ diastereoselectivity (45 examples, average 95.6 % ee ). These center axis are disposed distal fashion they constructed via two distinct migratory insertions that stereo‐determining under catalyst control.

Language: Английский

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Applications of Chiral Cyclopentadienyl (Cp^x) Metal Complexes in Asymmetric Catalysis

European Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 2020(42), P. 6512 - 6524

Published: July 21, 2020

Metal complexes containing cyclopentadienyl (Cp) ligands are versatile and robust catalysts widely applied in organic synthesis. During the last two decades chiral Cp x have been a variety of enantioselective transformations. Often associated with Group 9 metals (Co, Rh, Ir), also used combination early transition‐metals rare‐earth elements. In this minireview asymmetric reactions that successfully steered ligand metal discussed according to coordinated. Several designs diverse array reactions, particular C–H functionalisation, binaphthyl‐derived leading field. Challenges these derive from need for their multi‐step synthesis, recently new were designed, which can be accessed shorter sequences readily available starting materials.

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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Enantioselective and Diastereoselective C–H Alkylation of Benzamides: Synergized Axial and Central Chirality via a Single Stereodetermining Step

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(15), P. 9151 - 9158

Published: July 9, 2021

In this report, distally disposed axial and central chirality has been installed in a synergistic fashion via rhodium-catalyzed C–H alkylation of benzamides using N-arylmaleimide as the alkylating reagent, which enantio- diastereo-determining steps are merged into single one. The coupling system features mild reaction conditions, broad substrate scope, excellent diastereoselectivity. chiral induction enabled by judicious choice rhodium cyclopentadienyl catalyst that serves to control both orientation olefin unit prochiral C–N bond.

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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