Synthesis of Polycarbonyl Pyrroles via KSO-Mediated Oxidative Cyclization of Enamines.

A novel KSO-promoted oxidative cyclization of enamines is described. A variety of enamines having diverse functional groups and substitution patterns react well using KSO as the oxidant in the absence of catalyst. This protocol provides a very simple route for the synthesis of polycarbonyl pyrroles and has the advantages of readily available starting materials, mild reaction conditions, and a wide scope of substrates.