Chiral bifunctional ferrocenylphosphine catalyzed highly enantioselective [3 + 2] cycloaddition reaction†
Abstract
A series of air-stable ferrocenylphosphines LB1–LB8 were designed and prepared in high yields. (R,SFc)-ferrocenylphosphine LB5 was found to efficiently promote the asymmetric [3 + 2] cycloaddition of Morita–Baylis–Hillman carbonates with maleimides to afford the corresponding bicyclic imides with 84–99% ee and 67–99% yield. Interestingly, the configuration of these products was contrary to those reported in the literature.