Copper(I)‐Catalyzed Three‐Component Coupling of N‐Tosylhydrazones, Alkynes and Azides: Synthesis of Trisubstituted 1,2,3‐Triazoles

Abstract The copper(I)‐catalyzed three‐component reaction of N ‐tosylhydrazones, terminal alkynes and azides has been realized in an efficient and regioselective manner. This reaction constitutes a convenient method for the synthesis of 1,4,5‐trisubstituted 1,2,3‐triazoles from simple starting substrates. Mechanistically, the reaction involves the trapping of the copper(I) triazolide intermediate to form a copper carbene and subsequent migratory insertion and protonation. magnified image