Synthesis of 1,2′- and 1,3′-bipyrroles from 2- and 3-nitropyrroles

1,2′- and 1,3′-Bipyrroles, which are attractive precursors for the synthesis of bipyrrole-based natural products, are synthesized in one-pot from 2- and 3-nitropyrroles by a sequential nitro group reduction—Paal–Knorr pyrrole synthesis.