A facile access to N-sulfonylimidates and their synthetic utility for the transformation to amidines and amides

It is shown that N-sulfonylimidates can be efficiently prepared by a three-component coupling of terminal alkynes, sulfonyl azides, and alcohols with use of a copper catalyst and an amine base. The reaction is characterized by mild conditions, high selectivity, and tolerance with various functional groups. Facile transformation of imidates to amidines was also achieved by sodium cyanide. Additionally, a protocol for the extremely efficient Pd-catalyzed [3,3]-sigmatropic rearrangement of allylic sulfonimidates to N-allylic sulfonamides has been developed.