Cu(I)‐Catalyzed Three‐Component Coupling of Trifluoromethyl KetoneN‐Tosylhydrazones, Alkynes and Azides: Synthesis of Difluoromethylene Substituted 1,2,3‐Triazoles

A CuI ‐catalyzed three‐component coupling of trifluoromethyl ketone N ‐ tosylhydrazones, alkynes and azides has been developed . The reactionrepresents a straightforward method to access difluoromethylene substituted 1,2,3‐triazoles. Mechanistically, it has been proposed that the reaction follows a pathway involving the formation of Cu(I)triazolide intermediate, Cu(I) carbene formation, migratory insertion, and β ‐fluoride elimination. Thetransformation is featured by mild conditions, wide substrate scope and high efficiency.