Research Progress on Multicomponent Reactions of Sulfonyl Azides and Terminal Alkynes

In recent years, the copper-catalyzed multicomponent reactions involving sulfonyl azides and terminal alkynes have received much attention in organic chemistry. N-Sulfonyl ketenimine intermediates, generated in situ from the copper(I)-catalyzed cycloaddition of sulfonyl azides and terminal alkynes, could be trapped by various nucleophiles such as amines, alcohols and H2O, etc. In addition, the ketenimine intermediates could also react with a wide range of olefins though [2+2], [3+2] and [4+2] cycloadditions. Moreover, attack of the ketenimine by intramolecular nucleophilic functional group and the following rearrangement or sigma-shift course have become a powerful tool for the construction of diverse biologically and pharmacologically active heterocyclic compounds. In this paper, the research achievements recently in the important area are described.