Divergent Synthesis of Multisubstituted Unsymmetric Pyrroles and Pyrrolin‐4‐ones from Enamino Esters via Copper‐Catalyzed Aerobic Dimerization

Abstract

A facile synthetic method to access multisubstituted unsymmetric pyrrole and pyrrolin‐4‐one derivatives is disclosed. In the presence of Cu(OAc)2 and KOAc, substituted pyrrole derivatives are produced in good yields (up to 93 %) through oxidative cyclization of enamino esters. Meanwhile, using CuCl2 and TFA (trifluoroacetic acid), pyrrolin‐4‐one derivatives are obtained in excellent yields (up to 94 %) through 1,2‐aryl migration. A wide range of functional groups have been tolerated, and a reliable method for the synthesis of valuable multisubstituted pyrroles and pyrrolin‐4‐ones has been developed.