Highly Enantioselective Synthesis of Pyrroloindolones and Pyrroloquinolinones via an N-Heterocyclic Carbene-Catalyzed Cascade Reaction.

In this work, the NHC-catalyzed Michael/Mannich/lactamization cascade reaction of enals with either indole-2-carboxaldehyde-derived aldimines or indole-7-carboxaldehyde-derived aldimines is described. This protocol enables the rapid assembly of optically active pyrroloindolones and pyrroloquinolinones derivatives under mild conditions with high yields, excellent enantioselectivities, and a broad substrate scope.