Asymmetric [3+2]-Cycloaddition of Morita–Baylis–Hillman Carbonates with Maleimides Catalyzed by Chiral Ferrocenylphosphines

Abstract

New chiral ferrocenylphosphines LB1–LB9 were designed and prepared through simple synthetic approaches. These air-stable ferrocenylphosphines were applied to promote asymmetric [3+2]-cycloaddition of Morita–Baylis–Hillman carbonates with maleimides, among which LB7 was shown to have good catalytic activity to afford the corresponding multifunctional cyclopentenes in up to 59% yield and up to 53% ee under mild reaction conditions. A plausible reaction mechanism was proposed.