Regioselective Dearomative Amidoximation of Nonactivated Arenes Enabled by Photohomolytic Cleavage of N‐nitrosamides

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(8)

Published: Jan. 5, 2024

Abstract Dearomative spirocyclization reactions represent a promising means to convert arenes into three‐dimensional architectures; however, controlling the regioselectivity of radical dearomatization with nonactivated afford spirocyclizative 1,2‐difunctionalization other than its kinetically preferred 1,4‐difunctionalization is exceptionally challenging. Here we disclose novel strategy for dearomative 1,2‐ or 1,4‐amidoximation (hetero)arenes enabled by direct visible‐light‐induced homolysis N−NO bonds nitrosamides, giving rise various highly regioselective amidoximated spirocycles that previously have been inaccessible required elaborate synthetic efforts. The mechanism and origins observed regioselectivities were investigated control experiments density functional theory calculations.

Language: Английский

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Synthesis of Phenol–Pyridinium Salts Enabled by Tandem Electron Donor–Acceptor Complexation and Iridium Photocatalysis

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 3419 - 3429

Published: Feb. 16, 2024

Herein, we describe a dual photocatalytic system to synthesize phenol–pyridinium salts using visible light. Utilizing both electron donor–acceptor (EDA) complex and iridium(III) cycles, the C–N cross-coupling of unprotected phenols pyridines proceeds in presence oxygen furnish pyridinium salts. Photocatalytic generation phenoxyl radical cations also enabled nucleophilic aromatic substitution (SNAr) fluorophenol with an electron-poor pyridine. Spectroscopic experiments were conducted probe mechanism reaction selectivity. The unique reactivity these displayed several derivatization reactions, providing rapid access diverse chemical space.

Language: Английский

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C4-Selective C–H Borylation of Pyridinium Derivatives Driven by Electron Donor–Acceptor Complexes

Organic Letters, Journal Year: 2022, Volume and Issue: 24(51), P. 9452 - 9457

Published: Dec. 16, 2022

The photoinduced C4-selective C-H borylation of pyridines was achieved using electron donor-acceptor complexes derived from a Lewis base and N-amidopyridinium salts under external oxidant- photocatalyst-free conditions. Notably, the nucleophilic character phosphite-ligated boryl radicals enables addition radical to position C4 pyridinium afford C4-borylated heteroarenes that are otherwise difficult obtain. This approach provides versatile platform for installation both phosphite- amine-coordinated boron groups on series mild conditions, demonstrating excellent C4-positional selectivity pyridine scaffolds.

Language: Английский

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Photoredox Catalysis for the Synthesis of N‐CF₂H Compounds Using 1‐((N‐(difluoromethyl)‐4‐methylphenyl)‐sulfonamido)pyridin‐1‐ium Trifluoromethanesulfonate

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(30)

Published: May 26, 2023

Abstract N ‐(difluoromethyl)amino (−NCF 2 H) compounds are of great interest given their unique and underexplored physiochemical properties. The lack structural diversity in NCF H is likely due part to the shortage protocols for efficient installation. Presented herein a new shelf‐stable pyridinium reagent that enables direct installation ‐(difluoromethyl)sulfonamide moiety [N(Ts)CF H)] onto (hetero)arenes alkenes diversification aryl alkyl compounds. described protocol utilizes blue light photoredox catalysis displays broad functional group tolerance with excellent chemoselectivity. Additional transformations applicability towards continuous flow also demonstrated.

Language: Английский

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Photocatalytic vinyl radical-mediated multicomponent 1,4-/1,8-carboimination across alkynes and olefins/(hetero)arenes

Science China Chemistry, Journal Year: 2023, Volume and Issue: 67(2), P. 558 - 567

Published: Sept. 27, 2023

Language: Английский

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