Hydrosulfonylation of Unactivated Alkenes Involving Sulfonyl Radical Generation via Photocatalytic Activation of Symmetrical Disulfones by an Energy Transfer Mimicry

作者：Dries De Vos, Ana V. Cunha, Becky Bongsuiru Jei, Bert U. W. Maes · 发表于：ACS Catalysis · 年份：2024 · DOI：10.1021/acscatal.4c02866 · 被引用次数：19 · 研究领域：Sulfur-Based Synthesis Techniques、Radical Photochemical Reactions、Advanced Photocatalysis Techniques

A visible-light-photocatalyzed hydrosulfonylation of unactivated alkenes with symmetrical disulfones using 2,4,6-triisopropylthiophenol as a hydrogen atom donor (H-D) has been developed. Generation of two sulfonyl radicals from disulfones via activation with visible light photocatalysis is involved. Mechanistic studies rule out that two sulfonyl radicals are generated from a symmetrical disulfone via an energy transfer mechanism as previously found for lower oxidation state sulfur–sulfur-based reactants (i.e., thiosulfonates and disulfides). Instead, an energy transfer mimic process occurs. This involves a photoinduced electron transfer (PET) via oxidative quenching of the excited photocatalyst (*PC) with disulfone, which generates a sulfonyl radical and sulfinate byproduct, followed by the reduction of the oxidized photocatalyst (PC •+ ) with this byproduct (SET) generating the second sulfonyl radical and photocatalyst (PC). The hydrosulfonylation reaction can be performed in dimethyl carbonate at room temperature, features a broad functional group compatibility, and allows easy recycling of the generated disulfide byproduct provided 2,4,6-trisubstituted thiophenol is used as H-D. The visible-light-photocatalyzed hydrosulfonylation of unactivated alkenes has been compared with the state-of-the-art using green metrics.