CuI‐Catalyzed Alkyne–Azide “Click” Cycloadditions from a Mechanistic and Synthetic Perspective

Abstract Cu I ‐catalyzed alkyne–azide cycloaddition provides 1,4‐disubstituted 1,2,3‐triazoles with such efficiency and scope that the transformation has been described as “click” chemistry. An overview of the mechanism of this remarkable reaction is presented as a means to explain the myriad of experimental results, particularly the various methods of catalyst generation, solvent and substrate effects, and choice of base or ligand. Both solution‐phase and solid‐phase results are comprehensively examined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)