Phosphine-Catalyzed Domino [3 + 3] Cyclization of para-Quinamines with Morita-Baylis-Hillman Carbonates: Access to Hydroquinoline Derivatives.

A phosphine-catalyzed [3 + 3] cyclization strategy between para-quinamines and HCHO Morita-Baylis-Hillman (MBH) carbonates was discovered, delivering a series of highly functionalized hydroquinoline derivatives in moderate to good yields and excellent diastereoselectivity. Moreover, mechanistic insights, gram-scale experiments, and synthetic manipulations of the products were also discussed.