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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Atroposelective Synthesis of Pyridoindolones Bearing Two Remote Distinct C–N Axes through Cobalt-Catalyzed Enantioselective C–H Activation

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

C–N axially chiral compounds represent an important class of atropisomers that are prevalent in bioactive and material molecules. Despite recent advances synthetic methodologies, the asymmetric construction featuring multiple axes has been rarely explored, significantly limiting their further applications. Herein, we report a novel atroposelective synthesis diaxially pyridoindolones both six–five six–six through cobalt-catalyzed C–H annulation. This approach demonstrates exceptional efficiency, yielding diverse array with excellent yields atroposelectivities (60 examples, up to >99% yield, ee, >20:1 dr). Mechanistic studies revealed stereochemistry were generated fixed simultaneously during cyclometalation step, along unexpected amplification effect. The practicality this protocol is underscored by successful gram-scale syntheses various transformations, including formation phosphine ligand. Notably, photoluminescence quantum (ΦF 0.99) positive solvatochromism observed, coupled significant chiroptical properties, underscoring potential applications these organic fluorescent materials.

Language: Английский

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Enantioselective Cobaltaphotoredox-Catalyzed C–H Activation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(34), P. 24105 - 24113

Published: Aug. 15, 2024

The quest for sustainable strategies in molecular synthesis has spurred the emergence of photocatalysis as a particularly powerful technique. In recent years, application this context greatly promoted development asymmetric catalysis. Despite impressive advances, enantioselective photoinduced strong arene C-H activations by cobalt catalysis remain unexplored. Herein, we report strategy that merges organic photoredox and cobalt-catalyzed activation, enabling regio- stereoselective dual functionalization indoles an fashion. Thereby, assembly various chiral indolo[2,3-

Language: Английский

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Rh(III)-Catalyzed Redox-Neutral C–H Activation/Annulation of Oxadiazolones with Sulfoxonium Ylides to access oxadiazoloisoquinolinone

New Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Oxadiazolone-fused isoquinolines were synthesized via Rh( iii )-catalyzed [4+2] annulation and C–H activation, followed by acymethylation products with antidiabetic anti-inflammatory potential.

Language: Английский

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