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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Kinetic Resolution of Racemic Radicals in Asymmetric Photoredox Minisci Reactions with Azaarenes for Precise Construction of Two Non-adjacent Stereocenters

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

Published: March 11, 2025

Despite the significant potential of photocatalysis as a robust synthetic tool, high reactivity radicals often presents challenges in achieving optimal chemoselectivity. In this study, we demonstrate that inherent limitation can be strategically harnessed for asymmetric photoredox catalysis. By utilizing chiral catalyst to facilitate kinetic resolution between two enantiomers racemic radical intermediates, one enantiomer selectively undergoes desired transformation, while noncatalytic side reactions deplete other enantiomer. Consequently, an attractive three-component Minisci-type reaction involving bromides, homoallylic tertiary alcohols or amines, and azaarenes has been developed. This approach enables efficient assembly amines onto nonadjacent β-position azaarene-functionalized carbon stereogenic center with levels enantio- diastereoselectivity. Therefore, method not only allows direct utilization readily available feedstocks are challenging convert into prochiral via redox processes but also provides strategy synthesizing complex molecules multiple stereocenters.

Language: Английский

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Photocatalytic Iminothiolation of Alkenes via Monothiocarbonate Oxime Esters

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 6731 - 6738

Published: April 10, 2025

Language: Английский

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Photocatalytic Ring-Closing Metathesis/Amination of 1,6-Enynes and 1,7-Enynes: Synthesis of α,β-Unsaturated γ-Lactams and Quinolin-2-ones

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

Published: May 20, 2025

A photocatalyzed ring-closing metathesis/amination of 1,6-enynes and 1,7-enynes using alkyl oxime esters as both an alkene deconstruction auxiliary amination source is present for the synthesis α,β-unsaturated γ-lactams quinolin-2-ones. Preliminary mechanistic studies suggest that intramolecular 1,5-hydrogen atom transfer key to generation unstabilized radicals, which subsequently promote homolytic Cα-Cβ cleavage under driving force formation more stable captodative radicals.

Language: Английский

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Synthesis and Properties of Visible Radical Photoinitiators Based on Semi‐Indigo

ChemistrySelect, Journal Year: 2025, Volume and Issue: 10(21)

Published: May 28, 2025

Abstract Nowadays, with the development of light‐emitting diode (LED), developing photoinitiators compatible LED has emerged as a critical area research. The maximum absorption peak existing is between 200–400 nm, which not light sources. In this study, four hydrogen‐abstraction free radical (PIs) were synthesized by introducing aldehyde groups directly into semi‐indigo one‐step method at room temperature. Compared to benzophenone (BP) 257 wavelengths PI‐1, PI‐2, PI‐3, and PI‐4 exhibited redshift 507 523 496 494 respectively. These PIs demonstrated significant redshift, their extending beyond 600 nm. Meanwhile, under irradiation LED@ 520 nm (5 mW/cm 2 ), double bond conversion rate PI‐3 exceeds 98%. On other hand, migration stability curing system was evaluated employing an immersion extraction technique. mobility values recorded for 0.74%, 0.71%, 1.30%, 0.76%, respectively, substantially lower in comparison that BP 22.5%. Moreover, have excellent cell compatibility can be used 3D printing. findings highlight PI1–PI4 possesses long‐wavelength absorption, low migration, via straightforward process.

Language: Английский

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