Enantioselective Annulation of α,β-Unsaturated N -Acyliminium Ions with β-Keto Ester Enolates via Cooperative Palladium and Brønsted Acid Catalysis.

We herein report a cooperative palladium- and Brønsted acid-catalyzed strategy toward the first enantioselective annulation of in situ generated α,β-unsaturated N -acyliminium ions with chiral metal enolates. Novel polycyclic oxoisoindoles featuring three contiguous stereogenic centers have been obtained with typically good yields, outstanding enantiocontrol, and moderate to good diastereoselectivity. The utility of the process was further demonstrated by their conversion to synthetically valuable scaffolds.