Phosphine-Catalyzed Highly Enantioselective [3 + 3] Cycloaddition of Morita–Baylis–Hillman Carbonates with C,N-Cyclic Azomethine Imines

The first phosphine-catalyzed highly enantioselective [3 + 3] cycloaddition of Morita–Baylis–Hillman carbonates with C,N-cyclic azomethine imines is described. Using a spirocyclic chiral phosphine as the catalyst, a novel class of pharmaceutically interesting 4,6,7,11b-tetrahydro-1H-pyridazino­[6,1-a]­iso-quinoline derivatives were obtained in high yields with good to excellent diastereoselectivities and extremely excellent enantioselectivities (98–>99% ee).