Access to P‐ and Axially Chiral Biaryl Phosphine Oxides by Enantioselective Cp^xIr^III‐Catalyzed C−H Arylations

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(39), P. 12901 - 12905

Published: July 25, 2018

An enantioselective C-H arylation of phosphine oxides with o-quinone diazides catalyzed by an iridium(III) complex bearing atropchiral cyclopentadienyl (Cpx ) ligand and phthaloyl tert-leucine as co-catalyst is reported. The method allows access to a) P-chiral biaryl oxides, b) atropo-enantioselective construction sterically demanding backbones, also c) selective assembly axial compounds in excellent yields diastereo- enantioselectivities. Enantiospecific reductions provide monodentate chiral phosphorus(III) having structures backbones proven importance ligands asymmetric catalysis.

Language: Английский

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Rh(III)-Catalyzed Asymmetric Synthesis of Axially Chiral Biindolyls by Merging C–H Activation and Nucleophilic Cyclization

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(24), P. 9527 - 9532

Published: June 4, 2019

Enantiomeric access to pentatomic biaryls is challenging due their relatively low rotational barrier. Reported herein the mild and highly enantioselective synthesis of 2,3′-biindolyls via underexplored integration C–H activation alkyne cyclization using a unified chiral Rh(III) catalyst. The reaction proceeded initial followed by cyclization. A rhodacyclic intermediate has been isolated from stoichiometric activation, which offers direct mechanistic insight.

Language: Английский

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Enantioselective C(sp³)–H Amidation of Thioamides Catalyzed by a Cobalt^III/Chiral Carboxylic Acid Hybrid System

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(4), P. 1153 - 1157

Published: Nov. 27, 2018

Abstract Recent advances in Cp x M III catalysis (M=Co, Rh, Ir) have enabled a variety of enantioselective C(sp 2 )−H functionalization reactions, but 3 is still largely unexplored. We describe an asymmetric amidation thioamides using achiral Co /chiral carboxylic acid hybrid catalytic system, which provides easy and straightforward access to chiral β‐amino thiocarbonyl carbonyl building blocks with quaternary carbon stereocenter.

Language: Английский

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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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Transition Metal Catalyzed Enantioselective C(sp²)–H Bond Functionalization

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(23), P. 13748 - 13793

Published: Nov. 12, 2020

Direct catalytic transformation of C–H bonds to new functionalities has provided a powerful strategy synthesize complex molecular scaffolds in straightforward way. Unstinting efforts the synthetic community have helped overcome long-standing major challenge regioselectivity by introducing directing group concept. However, full potential cannot be realized unless activated are stereochemically controlled. The enantioselective bond functionalization could provide an imperative tool for sustainable way synthesizing chiral scaffolds. Despite intrinsic challenges achieving stereocontrol, developed different tools order achieve stereoselective functionalization. In this review, we discuss remarkable recent advances emerging area C(sp2)–H highlight and opportunities, emphasizing techniques so far.

Language: Английский

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Diverse Approaches for Enantioselective C−H Functionalization Reactions Using Group 9 Cp^xM^III Catalysts

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(33), P. 7346 - 7357

Published: Jan. 29, 2020

Transition-metal-catalyzed C-H functionalization reactions with Cp*MIII catalysts (M=Co, Rh, Ir) have found a wide variety of applications in organic synthesis. Albeit the intrinsic difficulties achieving catalytic stereocontrol using these due to their lack additional coordination sites for external chiral ligands and conformational flexibility Cp ligand, enantioselective Group 9 metal triad Cp-type been intensively studied since 2012. In this minireview, progress according type catalyst used are summarized discussed. The development Cpx complexes thereof, artificial metalloenzymes, carboxylate-assisted activations, alkylations assisted by carboxylic acids or sulfonates, transient directing groups

Language: Английский

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Chiral Cyclopentadienyl Cobalt(III) Complexes Enable Highly Enantioselective 3d-Metal-Catalyzed C–H Functionalizations

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(14), P. 5675 - 5680

Published: March 22, 2019

The synthesis of a set cobalt(III)-complexes equipped with trisubstituted chiral cyclopentadienyl ligands is reported, and their steric electronic parameters are mapped. application potential these complexes for asymmetric C-H functionalizations 3d-metals shown by the dihydroisoquinolones from N-chlorobenzamides broad range alkenes. transformation proceeds excellent enantioselectivities up to 99.5:0.5 er high regioselectivities. observed values outperform best rhodium(III)-based methods this reaction type. Moreover, challenging substrates such as alkyl alkenes also react regio- enantioselectivities.

Language: Английский

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Enantioselective Synthesis of Chiral‐at‐Sulfur 1,2‐Benzothiazines by Cp^xRh^III‐Catalyzed C−H Functionalization of Sulfoximines

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(47), P. 15539 - 15543

Published: Oct. 10, 2018

Abstract Sulfoximines with stereogenic sulfur atoms are attractive structural motifs in drug discovery. A direct catalytic enantioselective method for the synthesis of sulfur‐chiral 1,2‐benzothiazines from readily accessible diaryl sulfoximines is presented. Rhodium(III) complexes equipped chiral cyclopentadienyl ligands and paired suitable carboxylic acid additives engage an enantiodetermining C−H activation directed by sulfoximine group. Subsequent trapping rhodacycle a broad range diazoketones gives access to S‐chiral synthetically highly substitution patterns good yields enantioselectivities.

Language: Английский

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Cp*Co(III)/MPAA-Catalyzed Enantioselective Amidation of Ferrocenes Directed by Thioamides under Mild Conditions

Organic Letters, Journal Year: 2019, Volume and Issue: 21(6), P. 1895 - 1899

Published: March 6, 2019

Cp*Cobalt(III)-catalyzed enantioselective C-H amidation of ferrocenes using monoprotected amino acids (MPAAs) as chiral ligands was developed. The reaction performed under mild conditions in high yields (up to 97%) with moderate enantioselectivity 77.5:22.5 er), providing a promising strategy create planar chirality via base-metal-catalyzed activation.

Language: Английский

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Divergent Synthesis of Tunable Cyclopentadienyl Ligands and Their Application in Rh-Catalyzed Enantioselective Synthesis of Isoindolinone

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(16), P. 7379 - 7385

Published: April 7, 2020

A series of rhodium complexes bearing sterically and electronically tunable cyclopentadienyl ligands, prepared by utilizing Co2(CO)8-mediated [2+2+1] cyclization as a key step, were synthesized. In the presence 2.5 mol% CpmRh4, unprecedented enantioselective [4+1] annulation reaction benzamides alkenes was achieved with broad substrate scope under mild conditions, providing variety isoindolinones excellent regio- enantioselectivity (up to 94% yield, 97:3 er). Preliminary mechanistic studies suggest that involves an oxidative Heck intramolecular alkene hydroamination reaction.

Language: Английский

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