Cobalt(III)-Catalyzed Enantioselective C–H Functionalization: Ligand Innovation and Reaction Development

Accounts of Chemical Research, Год журнала: 2025, Номер unknown

Опубликована: Фев. 26, 2025

ConspectusIn contrast to precious transition metals, such as palladium and rhodium, the development of novel chiral ligands for enantioselective C-H functionalizations catalyzed by earth-abundant, cost-effective, environmentally friendly 3d metals poses substantial challenges, primarily due variable oxidation states, intricate coordination patterns, limited mechanistic insights. In this Account, we summarize our research endeavors in three types Co(III) catalysis: pseudotetrahedral achiral Cp*Co(III)/chiral carbonyl acid (CCA) catalysis, situ-generated octahedral cobalt(III) via cobalt/salicyloxazoline (Salox) Co(II)/chiral phosphoric (CPA) cooperative achieved through strategic ligand design. Our initial objective was achieve functionalization Cp*Co(III) catalysts with external ligands, aiming circumvent laborious preparation CpxCo(III) complexes. To end, developed several CCA incorporating non-covalent interactions (NCIs) a crucial design element. Next, address limitations associated lengthy synthesis Cp-ligated complexes difficulties modification, explored concept situ generation catalysis using commercially available cobalt(II) salts tailor-made ligands. This exploration led two innovative catalytic systems, namely, Co(II)/Salox Co(II)/CCA sequential catalysis. The emerged versatile strategy, demonstrating excellent enantioselectivities across range asymmetric reactions construct various molecules central, axial, planar, inherent chirality. facile single step, along ease further enhances versatility applicability approach. Moreover, successfully applied cobalt/Salox electro- photochemical-catalyzed functionalization, electrons or oxygen traceless oxidant, thereby eliminating need stoichiometric chemical oxidants. Through studies reaction developments, elucidated detailed structure-enantioselectivity relationships which are expected inform future endeavors. Finally, Co(II)/CPA enabled spiro-γ-lactams olefination/asymmetric [4 + 1] spirocyclization. Mechanistically, establishment stereochemistry occurs during cyclization where CPA serves both neutral Brønsted acid, stereoinduction independent cleavage step. We anticipate that insights advancements Account will inspire innovations drive progress metal-catalyzed reactions.

Язык: Английский

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Rhodium‐Catalyzed Atroposelective Access to Axially Chiral Olefins via C−H Bond Activation and Directing Group Migration

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(1)

Опубликована: Окт. 22, 2021

Axially chiral open-chain olefins represent an underexplored class of platform. In this report, two classes tetrasubstituted axially acyclic have been accessed in excellent enantioselectivity and regioselectivity via C-H activation (hetero)arenes assisted by a migratable directing group en route to coupling with sterically hindered alkynes. The indoles bearing N-aminocarbonyl afforded C-N acrylamides the assistance racemic zinc carboxylate additive. DFT studies suggest β-nitrogen elimination-reinsertion pathway for migration. Meanwhile, employment N-phenoxycarboxamide delivered C-C enamides migration oxidizing group. Experiments that both cases (hetero)arene substrate adopts well-defined orientation during activation, which turn determines disposition alkyne migratory insertion. Synthetic applications representative are demonstrated.

Язык: Английский

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Synthesis of Chiral Spirolactams via Sequential C−H Olefination/Asymmetric [4+1] Spirocyclization under a Simple Co^II/Chiral Spiro Phosphoric Acid Binary System

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(43), С. 23187 - 23192

Опубликована: Авг. 26, 2021

Abstract An unprecedented enantioselective synthesis of spiro‐γ‐lactams via a sequential C−H olefination/asymmetric [4+1] spirocyclization under simple Co II /chiral spiro phosphoric acid (SPA) binary system is reported. A range biologically important are obtained with high levels enantioselectivity (up to 98 % ee ). The concise, asymmetric an aldose reductase inhibitor was successfully achieved. Notably, contrast previous reports that relied on the use cyclopentadienyl or its derivatives (achiral Cp*, Cp tBu , chiral x ) ligated III complexes requiring tedious steps prepare, cheap and commercially available cobalt(II) acetate tetrahydrate used as efficient precatalyst.

Язык: 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, Год журнала: 2021, Номер 11(15), С. 9151 - 9158

Опубликована: Июль 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.

Язык: Английский

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Asymmetric C–H Activation for the Synthesis of P- and Axially Chiral Biaryl Phosphine Oxides by an Achiral Cp*Ir Catalyst with Chiral Carboxylic Amide

ACS Catalysis, Год журнала: 2021, Номер 12(1), С. 193 - 199

Опубликована: Дек. 14, 2021

The catalytic synthesis of P- and axially chiral biaryl phosphine oxides was realized via the Cp*Ir-catalyzed asymmetric C–H coupling tertiary substituted with diarylacetylenes. carboxylic amides were used to control stereoselectivity in activation, enabling construction up 96% ee. Transformation products into trivalent ligands has also been demonstrated.

Язык: Английский

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Ruthenium(II)/Imidazolidine Carboxylic Acid‐Catalyzed C−H Alkylation for Central and Axial Double Enantio‐Induction

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(47)

Опубликована: Сен. 15, 2022

Enantioselective C-H activation has surfaced as a transformative toolbox for the efficient assembly of chiral molecules. However, despite major advances in rhodium and palladium catalysis, ruthenium(II)-catalyzed enantioselective thus far largely proven elusive. In contrast, we herein report on highly regio-, diastereo- alkylation. The key to success was represented by identification novel C2-symmetric imidazolidine carboxylic acids (CICAs), which are easily accessible one-pot fashion, effective ligands. This ruthenium/CICA system enabled installation central axial chirality, featured excellent branched linear ratios with generally >20 : 1 dr up 98 2 er. Mechanistic studies experiment computation were carried out understand catalyst mode action.

Язык: Английский

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Binaphthyl Scaffold: A Class of Versatile Structure in Asymmetric C–H Functionalization

ACS Catalysis, Год журнала: 2022, Номер 12(15), С. 9359 - 9396

Опубликована: Июль 18, 2022

Over the past decades, transition metal-catalyzed enantioselective C–H functionalization has emerged as a straightforward and powerful tool for rapid access to chiral molecules. The enormous advances achieved in this emerging area largely rely on development of ligands that can enable both high levels enantiocontrol efficiency. Chiral bearing binaphthyl scaffolds have been proven be versatile asymmetric due their availability, unique stereochemical features, ease fine-tuning steric electronic properties. In Review, we summarized advance applications basis scaffold functionalization.

Язык: Английский

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Coordination-assisted, transition-metal-catalyzed enantioselective desymmetric C–H functionalization

Organic Chemistry Frontiers, Год журнала: 2022, Номер 9(5), С. 1458 - 1484

Опубликована: Янв. 1, 2022

Recent advances in transition-metal-catalyzed enantioselective desymmetric C–H functionalization are summarized.

Язык: Английский

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Enantioselective C−H functionalization reactions enabled by cobalt catalysis

Chem Catalysis, Год журнала: 2022, Номер 2(11), С. 2965 - 2985

Опубликована: Сен. 16, 2022

Язык: Английский

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Ir(III)-Catalyzed Asymmetric C–H Activation/Annulation of Sulfoximines Assisted by the Hydrogen-Bonding Interaction

ACS Catalysis, Год журнала: 2022, Номер 12(15), С. 9083 - 9091

Опубликована: Июль 14, 2022

Transition-metal-catalyzed asymmetric C–H activation reactions generally rely on the design of ligands with sterically bulky groups to create a chiral environment for enantioinduction through steric repulsion. Here we describe an Ir(III)-catalyzed enabled by noncovalent interactions. A broad range sulfur-stereogenic sulfoximines was prepared in high yields excellent enantioselectivities via activation/annulation diazo compounds. Desymmetrization, kinetic resolution, and parallel resolution are compatible this protocol. Detailed DFT calculations suggested that N–H···O hydrogen bonding interaction between sulfoximine carboxylic acid ligand crucial enantiocontrol. Moreover, iridacycle intermediates were isolated, characterized, subjected stoichiometric reactions. Computational experimental studies cleavage step rate- enantio-determining step.

Язык: Английский

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