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).本文报道了首例膦催化的莫里塔-贝利斯-希尔曼碳酸酯（Morita–Baylis–Hillman carbonates）与C,N-环状甲亚胺亚胺（C,N-cyclic azomethine imines）之间的高对映选择性[3+3]环加成反应。以螺环手性膦作为催化剂，可获得一类兼具药用价值的新型4,6,7,11b-四氢-1H-吡嗪并[6,1-a]异喹啉衍生物，产物收率优异，非对映选择性良好至优秀，且对映选择性极为出色（对映体过量值98~>99% ee）。