Enantioselective α‐Arylation of Cyclic β‐Ketoamides with a Quinone Monoimine

A facile and direct method for the construction of enantioenriched α‐arylated quaternary β‐ketoamides was developed. By employing a chiral bifunctional thiourea‐tertiary amine as catalyst, enantioselective α‐arylation of cyclic β‐ketoamides with a quinone monoimine proceeded smoothly to afford various α‐arylated quaternary β‐ketoamides in good yields (up to 97%) with moderate to good enantioselectivities (up to 85% ee). Generally, benzo six‐membered cyclic β‐ketoamides exhibited better enantioselection than benzo five‐membered cyclic β‐ketoamides.