Synthesis of pyrrole-2,3,4,5-tetracarboxylates via a copper-catalyzed reaction of amine with but-2-ynedioate

A copper-catalyzed reaction of amine with but-2-ynedioate gives rise to pyrrole-2,3,4,5-tetracarboxylates in moderate to good yields. The reaction proceeds in the presence of dioxygen with the formation of three bonds during the process. (C) 2013 Elsevier Ltd. All rights reserved.