Rhodium(III)-Catalyzed [3 + 2] Annulation of Diazo Compounds with Enaminones for Constructing Polysubstituted NH-Pyrroles

A simple and efficient approach to access polysubstituted NH-pyrroles by a cascade annulation of diazo compounds with β-enaminones has been developed. This transformation proceeds via nucleophilic addition of the enaminones to rhodium carbenoid and subsequential intramolecular annulation, demonstrating a broad substrate scope with good functional group compatibility. Notably, it offers a practical protocol to densely substituted pyrroles bearing NH and carbonyl groups, which can be further diversified through a range of downstream transformations.