Photoredox-Catalyzed Direct C(sp²)-H Difluoromethylation of Hydrazones with Difluoromethyltriphenylphosphonium Salt via Aminyl Radical/Polar Crossover

This study describes an efficacious and generally applicable synthetic strategy for the incorporation of biologically and physiologically prominent difluoromethyl entity into synthetically crucial hydrazone scaffolds with bench-stable and easily accessible difluoromethyltriphenylphosphonium bromide. The broad substrate scope, excellent functional group compatibility, feasibility of step and atom economical one-pot synthetic manipulation, and environmentally benign and mild reaction conditions rendered this methodology an efficient tool for the preparation of synthetically and pharmaceutically prominent fluorine-containing imino compounds.