Copper-Mediated Photoinduced Trifluoromethylation of Arylsulfonium Salts with Yagupolskii–Umemoto Reagent

The copper-mediated, visible-light-induced trifluoromethylation of arylsulfonium salts using the Yagupolskii-Umemoto reagent as the trifluoromethyl source is described. This reaction allowed the convenient and efficient synthesis of CF₃-containing arenes from different sulfonium salts under mild conditions, featuring excellent chemoselectivity, good functional group compatibility, and a broad range of substrates. Mechanistically, the present reductive trifluoromethylation likely involves the formation of a key [CuCF₃] intermediate from the Yagupolskii-Umemoto reagent and its subsequent reduction and cross-coupling of an arylsulfonium salt. This transformation represents the first cross-coupling of two electrophilic sulfonium-based reagents and enables the late-stage functionalization of structurally diversified drug molecules.