Recent advances in photoinduced trifluoromethylation and difluoroalkylation

Abstract

Recent advances in photoinduced trifluoromethylation and difluoroalkylation under photocatalysis are summarized. Most of the photoredox reactions proceed efficiently under mild conditions with simple operation. Various fluorinated reagents are developed and applied in different transformations. Usually, the photocatalyst in a photocatalytic cycle is initially stimulated to the excited state in the presence of visible light, which then provides an electron to the fluorinated reagent to release a CF₃ radical or CF₂ radical. The subsequent radical addition to an unsaturated bond with further transformations would produce the corresponding fluorinated products. Alkenes, alkynes, isocyanides, and arenes are frequently employed as substrates for access to fluorochemicals. The advantages of trifluoromethylation and difluoroalkylation under photocatalysis including mild reaction conditions, good functional group tolerance, and experimental ease will make the approaches attractive for further applications.