Cobalt‐Catalyzed Enantioselective C−H Carbonylation towards Chiral Isoindolinones

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(10)

Published: Jan. 11, 2024

Transition metal-catalyzed enantioselective C-H carbonylation with carbon monoxide, an essential and easily available C1 feedstock, remains challenging. Here, we disclosed unprecedented catalyzed by inexpensive readily cobalt(II) salt. The reactions proceed efficiently through desymmetrization, kinetic resolution, parallel affording a broad range of chiral isoindolinones in good yields excellent enantioselectivities (up to 92 % yield 99 ee). synthetic potential this method was demonstrated asymmetric synthesis biological active compounds, such as (S)-PD172938 (S)-Pazinaclone. resulting also serve ligands cobalt-catalyzed annulation alkynes construct phosphorus stereocenter.

Language: Английский

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Electrooxidative Rhodium(III)/Chiral Carboxylic Acid‐Catalyzed Enantioselective C−H Annulation of Sulfoximines with Alkynes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(15)

Published: Jan. 30, 2024

Abstract The combination of achiral Cp*Rh(III) with chiral carboxylic acids (CCAs) represents an efficient catalytic system in transition metal‐catalyzed enantioselective C−H activation. However, this hybrid catalysis is limited to redox‐neutral activation reactions and the adopt oxidative remains elusive pose a significant challenge. Herein, we describe development electrochemical Cp*Rh(III)‐catalyzed annulation sulfoximines alkynes enabled by acid (CCA) operationally friendly undivided cell at room temperature. A broad range enantioenriched 1,2‐benzothiazines are obtained high yields excellent enantioselectivities (up 99 % yield 98 : 2 er). practicality method demonstrated scale‐up reaction batch reactor external circulation. crucial intermediate isolated, characterized, transformed, providing rational support for Rh(III)/Rh(I) electrocatalytic cycle.

Language: Английский

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

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 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.

Language: Английский

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Nitrene Transfer Reactions for Asymmetric C–H Amination: Recent Development

European Journal of Organic Chemistry, Journal Year: 2019, Volume and Issue: 2020(8), P. 909 - 916

Published: Dec. 18, 2019

C–H bonds are ubiquitous and abundant in organic molecules. If could be directly converted to desired functional groups a chemo‐, site‐, stereoselective manner, functionalization would strong useful tool for synthesis. Recent developments catalytic enzymatic chemistry have achieved highly sustainable selective nitrene insertion. Initially, amination was inspired by model studies on oxidation used iminoiodinanes, nitrogen analogs of iodosobenzene, as precursors. Transition‐metal/iminoiodinane systems well studied established. These can introduce sulfonamide with excellent stereoselectivity, albeit co‐production iodobenzene waste material. Fortunately, the atom economics this methodology were improved introducing sources such azide compounds 1,2,4‐dioxazol‐5‐one derivatives. In review, we present details these respect their catalysts sources.

Language: Английский

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Cobalt-Catalyzed Enantioselective Hydroarylation of 1,6-Enynes

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(20), P. 9510 - 9517

Published: April 25, 2020

An asymmetric hydroarylative cyclization of enynes involving a C–H bond cleavage is reported. The cobalt-catalyzed cascade generates three new bonds in an atom-economical fashion. products were obtained excellent yields and enantioselectivities as single diastereo- regioisomers. Preliminary mechanistic studies indicate that the reaction shows no intermolecular crossover. This work highlights potential cobalt catalysis functionalization enantioselective domino reactivity.

Language: Английский

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