Visible Light-Induced Aromatic Difluoroalkylation

Difluoroalkylated aromatics are important structural motifs in pharmaceutical and agrochemical applications. Herein, we report their synthesis by a mild, efficient, and convenient method using visible light photoredox catalysis. A variety of unactivated aromatics were difluoroalkylated with ethyl 2-bromo-2,2-difluoroacetate (BrCF₂CO₂Et) in the presence of the triscyclometalated Ir complex fac-[Ir(ppy)₃] under visible light irradiation at room temperature. It is shown that reaction outcomes containing the CF₂CO₂Et moiety can be converted to a variety of other CF₂-containing aromatics, demonstrating the synthetic utility of the present method.