Photoinduced iridium-cobaloxime mediated alkene C(sp2)–CF2H cross-coupling: difluoromethylation of ketene dithioacetals

Abstract

The difluoromethylation of various substrates has experienced significant advancements with the rapid development of photoinduced reactions. However, the difluoromethylation of alkenes is usually limited to addition reactions, with C(sp²)–CF₂H construction mostly occurring in heteroaromatics. This study presents a novel iridium photocatalyst–cobaloxime co-mediated difluoromethylation of a type of polarized internal alkene, ketene dithioacetals. Mechanistic investigations highlighted the crucial role of cobaloxime, and subsequent transformations further demonstrated the practical value of the products. This approach offers a promising avenue for utilizing partially fluorinated alkyl sulfinates in radical fluoroalkylation reactions under mild conditions.