Enantioselective electrochemical cobalt-catalyzed aryl C–H activation reactions

Science, Год журнала: 2023, Номер 379(6636), С. 1036 - 1042

Опубликована: Март 10, 2023

Enantioselective redox transformations typically rely on costly transition metals as catalysts and often stoichiometric amounts of chemical agents well. Electrocatalysis represents a more sustainable alternative, in particular through the use hydrogen evolution reaction (HER) place oxidant. In this work, we describe strategies for HER-coupled enantioselective aryl carbon-hydrogen bond (C-H) activation reactions using cobalt precious metal catalyst asymmetric oxidation. Thus, highly nitrogen-hydrogen (C-H N-H) annulations carboxylic amides were achieved, which gave access to point axially chiral compounds. Furthermore, cobalt-mediated electrocatalysis enabled preparation various phosphorus (P)-stereogenic compounds by selective desymmetrization dehydrogenative C-H reactions.

Язык: Английский

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Base‐Promoted Electrochemical Co^II‐catalyzed Enantioselective C−H Oxygenation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(21)

Опубликована: Март 20, 2023

Metalla-electrocatalyzed C-H oxygenation represents one of the most straightforward and sustainable approaches to access valuable oxygenated molecules. Despite significant advances, development enantioselective electrochemical reaction is very challenging remains elusive. Herein, we described first CoII -catalyzed alkoxylation. A broad range enantioenriched alkoxylated phosphinamides were obtained in good yields with excellent enantioselectivities (up 98 % yield >99 ee). An unusual cobalt(III) alcohol complex was prepared fully characterized, which proven be a key intermediate this alkoxylation reaction. Mechanistic studies revealed that oxidation CoIII CoIV facilitated by base whole process proceeded through cobalt(III/IV/II) catalytic cycle.

Язык: Английский

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Cobalt-catalyzed atroposelective C−H activation/annulation to access N−N axially chiral frameworks

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Авг. 29, 2023

The N-N atropisomer, as an important and intriguing chiral system, was widely present in natural products, pharmaceutical lead compounds, advanced material skeletons. anisotropic structural characteristics caused by its special axial rotation have always been one of the challenges that chemists strive to overcome. Herein, we report efficient method for enantioselective synthesis axially frameworks via a cobalt-catalyzed atroposelective C-H activation/annulation process. reaction proceeds under mild conditions using Co(OAc)2·4H2O catalyst with salicyl-oxazoline (Salox) ligand O2 oxidant, affording variety products high yields enantioselectivities. This protocol provides approach facile construction atropisomers further expands range derivatives. Additionally, electrocatalysis, desired were also successfully achieved good excellent efficiencies

Язык: Английский

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Cobalt-Catalyzed Enantioselective C–H Annulation with Alkenes

ACS Catalysis, Год журнала: 2023, Номер 13(7), С. 4250 - 4260

Опубликована: Март 13, 2023

Herein, we disclose an efficient cobalt-catalyzed enantioselective C–H activation and annulation of benzamides with alkenes. This transformation is facilitated via the commercially available cobalt(II) catalyst in presence easily prepared chiral salicyl-oxazoline (Salox) ligand, which provides facile access to (R) or (S) enantiomers dihydroisoquinolone derivatives. It noticeable that reaction proceeded efficiently within extremely short time from 10 30 min under mild conditions. A broad range alkenes bear various functional substituents have been shown good compatibility deliver targeted products high yields enantioselectivities (51 examples, up 98% yield 99% ee). The gram scale experiment removal directing group further demonstrate practicability this protocol potential industrial applications. Density theory calculations elucidate mechanism, spin-state change olefin insertion step accelerates subsequent C–N reductive elimination, identified as stereo-determining step. AIM analysis indicates π interactions are vital for controlling switching stereoselectivity.

Язык: Английский

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Cobalt‐Catalyzed Enantioselective C−H Carbonylation towards Chiral Isoindolinones

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(10)

Опубликована: Янв. 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.

Язык: Английский

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

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(15)

Опубликована: Янв. 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.

Язык: Английский

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Cobalt‐Catalyzed Asymmetric Aza‐Nozaki–Hiyama–Kishi (NHK) Reaction of α‐Imino Esters with Alkenyl Halides

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(7)

Опубликована: Янв. 2, 2024

Chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi (NHK) reaction represents one of the most powerful approaches for formation chiral carbon-heteroatom bond. However, construction sterically encumbered tetrasubstituted stereocenter through NHK still posts a significant challenge. Herein, we disclose cobalt-catalyzed aza-NHK ketimine with alkenyl halide to provide convenient synthetic approach manufacture enantioenriched α-vinylic amino acid. This protocol exhibits excellent functional group tolerance 99 % ee in cases. Additionally, this asymmetric reductive method is also applicable aldimine access trisubstituted stereogenic centers.

Язык: Английский

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Recent Advances in Asymmetric Organometallic Electrochemical Synthesis (AOES)

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

Опубликована: Янв. 19, 2025

ConspectusIn recent years, our research group has dedicated significant effort to the field of asymmetric organometallic electrochemical synthesis (AOES), which integrates electrochemistry with transition metal catalysis. On one hand, we have rationalized that compounds can serve as molecular electrocatalysts (mediators) reduce overpotentials and enhance both reactivity selectivity reactions. other conditions for catalysis be substantially improved through electrochemistry, enabling precise modulation metal's oxidation state by controlling potentials regulating electron transfer rate via current adjustments. This synergistic approach addresses key challenges inherent in traditional catalysis, particularly those related use redox-active chemical reagents. Furthermore, redox conveniently tuned modifying their ligands, thereby governing reaction regioselectivity stereoselectivity. As a result, AOES emerged powerful promising tool chiral compounds.In this Account, summarize contextualize efforts AOES. Our primary strategy involves leveraging controllability potential regulate organometallics, facilitating desired An efficient platform was established under mild conditions, significantly reducing reliance on been systematically categorized into three sections based distinct electrolysis modes: combined anodic oxidation, cathodic reduction, paired electrolysis. In each section, highlight innovative discoveries tailored unique characteristics respective modes.In many transformations, metal-catalyzed reactions involving reagents utilizing exhibit similar reactivities. However, also observed notable differences certain cases. These findings include following: (1) Enhanced efficiency synthesis: instance, Rh-catalyzed enantioselective functionalization C–H bonds demonstrates superior efficiency. (2) Expanded scope transformations: previously challenging achieved due tunability potentials. A example is reductive coupling aryl chlorides, expands range accessible transformations. Additionally, mechanistic studies explore techniques intrinsic such controlled experiments, impact electrode materials catalyst performance, cyclic voltammetry studies. investigations provide more intuitive understanding behavior catalysts study mechanisms, guide design new catalytic systems.The advancements offer robust environmentally friendly sustainable selective By integrating developed versatile organic not only enhances but reduces environmental impact. We anticipate Account will stimulate further innovation realm AOES, leading discovery systems development synthetic methodologies.

Язык: Английский

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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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Cobaltaelectro-Catalyzed C–H Annulation with Allenes for Atropochiral and P-Stereogenic Compounds: Late-Stage Diversification and Continuous Flow Scale-Up

ACS Catalysis, Год журнала: 2023, Номер 13(14), С. 9713 - 9723

Опубликована: Июль 11, 2023

The 3d metallaelectro-catalyzed C-H activation has been identified as an increasingly viable strategy to access valuable organic molecules in a resource-economic fashion under exceedingly mild reaction conditions. However, the development of enantioselective is very challenging and its infancy. Here, we disclose merger cobaltaelectro-catalyzed with asymmetric catalysis for highly annulation allenes. A broad range C-N axially chiral P-stereogenic compounds were thereby obtained good yields up 98% high enantioselectivities >99% ee. practicality this approach was demonstrated by diversification complex bioactive drug well decagram scale electrocatalysis continuous flow.

Язык: Английский

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