In(OTf)3-catalysed one-pot versatile pyrrole synthesis through domino annulation of α-oxoketene-N,S-acetals with nitroolefins

Abstract

In(OTf)₃-catalyzed robust and sustainable one-pot access to previously unknown and synthetically demanding polysubstituted pyrroles via [3 + 2] annulation of α-oxoketene-N,S-acetals with β-nitrostyrenes has been achieved under solvent-free conditions. The merit of this domino Michael addition/cyclization sequence is highlighted by its operational simplicity, short reaction time (5–10 min), good to excellent yields, tolerance of a large variety of functional groups, and efficiency of producing two new (C–C and C–N) bonds and one highly functionalized pyrrole ring in a single operation, which make it an ideal alternative to existing methods.