Highly enantioselective Michael additions in water catalyzed by a PS-supported pyrrolidine
E. Alza, X. C. Cambeiro, C. Jimeno, M. A. Pericàs
Org. Lett. 2007, 9, 3717-3720
Abstract: The development of a highly efficient, polymer-supported organocatalyst for the Michael addition of ketones to nitroolefins is described. A 1,2,3-triazole ring, constructed through a click 1,3-cycloaddition, plays the double role of grafting the chiral pyrrolidine monomer onto the polystyrene backbone and of providing a structural element, complementary to pyrrolidine, key to high catalytic activity and enantioselectivity. Optimal operation in water and full recyclability make the triazole linker attractive for the immobilization of organocatalysts.