N-Heterocyclic Carbene-Catalyzed [3 + 2] Annulation of Bromoenals with 3-Aminooxindoles: Highly Enantioselective Synthesis of Spirocyclic Oxindolo-γ-Lactams.

The chiral N-heterocyclic carbene-catalyzed [3 + 2] annulation of α-bromoenals and 3-aminooxindoles was developed, giving the corresponding spirocyclic oxindolo-γ-lactams in good yields with high diastereoselectivities and enantioselectivities.