Cu(II)-Catalyzed Reaction of Ethynyl Methylene Cyclic Carbamates and Amines: Synthesis of Polysubstituted Pyrroles.

A copper-catalyzed efficient, operationally simple, general method for straightforward syntheses of polysubstituted pyrroles employing ethynyl methylene cyclic carbamates as precursors reacting with commercially available amines was first reported. A wide variety of polysubstituted pyrroles were obtained in acceptable to good yields under mild conditions. This protocol features broad substrate scope, high functional group tolerance, and easy operation, therefore enabling late-stage functionalization and rapid synthesis of bioactive compounds, including structurally complex marketed drugs and natural products. In addition, a scale-up experiment further highlighted the synthetic utility.