Visible-Light-Induced Energy-Transfer-Mediated Hydrofunctionalization and Difunctionalization of Unsaturated Compounds via Sigma-Bond Homolysis of Energy-Transfer Acceptors

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(3), P. 1854 - 1941

Published: Jan. 17, 2025

Over the past decade, visible-light-mediated energy-transfer (EnT) catalysis, particularly triplet–triplet (TTEnT) has emerged as a mild and environmentally friendly approach for diverse organic synthetic transformations. In contrast to photoredox which typically requires sacrificial electron donors or acceptors complete catalytic cycle, EnT photocatalysis generally proceeds with high atom economy while minimizing generation of wasteful byproducts. Furthermore, successful catalysis is contingent upon precise control redox potentials both photocatalysts substrates, strategies are primarily influenced by triplet energy compatibility between these entities. Considering growing importance photocatalysis, well hydrofunctionalization difunctionalization reactions in synthesis, this review systematically summarizes significant advancements EnT-enabled unsaturated compounds via sigma-bond homolysis over decade. Special emphasis placed on elucidating substrate scopes mechanistic scenarios. Additionally, discusses versatile applications methodologies addresses current challenges opportunities within evolving research field. This structured into six main categories based different types sigma-bonds undergoing homolysis. These include transformations mediated 1) N–O bond oxime esters other N,O-radical precursors; 2) N–S N-sulfonyl imines N,S-radical 3) chalcogen–chalcogen disulfides oxy/thio/selenosulfonates; 4) C–S tri/difluoromethylated sulfinates, acetylenic triflones, arylsulfonium salts; 5) C–X (X = halogen) halides; 6) acceptors. Through providing theoretical backgrounds along comprehensive overview currently employed acceptors, photosensitizers, contemporary EnT-induced compounds, aims serve an invaluable resource future innovations rapidly

Language: Английский

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Photosensitized Imino-Thiocyanation of Alkenes

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

A metal-free photosensitized 1,2-imino-thiocyanation of olefins has been established by using the easily accessible bifunctional reagent S-cyano-N-(diphenylmethylene) thiohydroxylamine. wide range were successfully transformed into corresponding β-iminothiocyanates in moderate to high yields. This protocol stands out for its nature, broad substrate compatibility, and atom step economy, providing an effective strategy assembling β-amino thiocyanate-containing scaffolds.

Language: Английский

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Direct Synthesis of 2-Hydroxytrifluoroethylacetophenones via Organophotoredox-Mediated Net-Neutral Radical/Polar Crossover

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(16), P. 11682 - 11692

Published: Aug. 1, 2024

Alkene difunctionalization is a very attractive tool in synthetic organic chemistry. Herein, we disclose an operationally and practically simple method to access 2-hydroxytrifluoroethylacetophenones from styrene derivatives via photoredox catalysis. This light-mediated transformation promotes the generation of 1-hydroxy-2,2,2-trifluoroethyl carbon-centered radical as key synthon, which undergoes Giese addition with styrenes followed by Kornblum oxidation process. The presented not only mild cost-effective, but also utilizes photocatalyst DMSO oxidant. Experimental investigations support operative mechanism net-neutral radical/polar crossover.

Language: Английский

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EDA-Enabled Three-Component Polarity-Crossover Cyclization: Modular Installation of Fully Substituted γ-Lactams

Organic Letters, Journal Year: 2024, Volume and Issue: 26(44), P. 9598 - 9603

Published: Oct. 28, 2024

A photoinduced three-component radical addition-aminalization cascade was accomplished, enabling rapid assembly of a wide range densely functionalized γ-lactams. Key to this transformation is the electron-donor-acceptor (EDA) generation enamine and in situ trapping an iminium intermediate with bromodifluoroacetamide. This rationally designed protocol fully takes advantage polarity crossover (enamine-iminium) process, providing modular previously inaccessible scaffolds. The reaction proceeds under mild conditions excellent regio- diastereoselectivity, which amenable structurally varied substrates pharmaceuticals.

Language: Английский

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Regio- and Stereoselective β-Sulfonylamination of Alkynes via Photosensitized Bifunctional N–S Bond Homolysis

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 4, 2024

Nitrogen central radicals (NCRs) are versatile synthetic intermediates for creating functional nitrogen-containing molecules. Herein, a photosensitized β-sulfonylamination of terminal alkynes as well acetylene has been established by employing N-sulfonyl heteroaromatics bifunctional reagents (BFRs) to efficiently deliver (E)-β-sulfonylvinylamines with excellent regio- and stereoselectivities. Mechanistic studies suggest base-accelerated energy transfer (EnT) photocatalysis involving aromatic NCR formation, radical addition alkynes, sulfonylation processes.

Language: Английский

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Visible Light‐Promoted Aerobic Oxidation of α‐Silyl Styrenes with Alcohols

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: 42(24), P. 3243 - 3247

Published: Aug. 24, 2024

Comprehensive Summary A mechanistically distinctive visible‐light‐promoted metal‐free aerobic oxidation of alkenyl silanes with alcohols was disclosed to efficiently construct α ‐alkoxy ketones under mild conditions. The primary, secondary, and tertiary could be used as reactants. protocol carried out on a gram‐scale. Various derivatizations products conducted. Mechanistic studies indicated the reaction initiated by single‐electron silanes, rather than radical addition silanes.

Language: Английский

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