Organocatalytic Enantioselective [1+4] Annulation of Morita-Baylis Hillman Carbonates with Electron-Deficient Olefins: Access to Chiral 2,3-Dihydrofuran Derivatives

A reaction has been developed for the chiral phosphine-catalyzed enantioselective [1 + 4] annulation of MoritaBaylisHillman carbonates with electron-deficient olefins via a Michael alkylation process. MoritaBaylisHillman carbonates reacted smoothly with beta,?-unsaturated a-keto ester and a,beta-unsaturated ketone substrates under 1,2-bis[(2R,5R)-2,5-dimethylphospholano]benzene monoxide catalysis to furnish a wide range of optically a(c)tive 2,3-dihydrofurans in high yields (up to 95%) with excellent asymmetric induction (up to >99% ee, >20:1 dr). This protocol represents an efficient strategy for the synthesis of optically active multifunctional 2,3-dihydrofurans via an asymmetric Michael alkylation domino reaction.