Cu-catalyzed oxygen-transferring hydrazonation of enynones

Abstract

An unprecedented Cu-catalyzed oxygen-transferring hydrazonation reaction of enynones with arylsulfonylhydrazines has been developed. Featuring high efficiency, broad substrate scope and mild reaction conditions, this protocol provides a practical alcohol-free approach to access various bio-related aryl–alkenyl and aryl–aryl sulfonylhydrazones containing carbonyl groups in up to 97% yields, which are challenging to synthesize via conventional methods. The utility of this reaction is further demonstrated by transformation of the obtained molecules into diverse nitrogen-containing heterocyclic compounds and alkenyl or hydroxyl derivatives.