Highly enantioselective synthesis of warfarin and its analogs catalysed by primary amine-phosphinamide bifunctional catalysts.

An efficient enantioselective Michael addition of 4-hydroxycoumarin to α,β-unsaturated ketones catalysed by primary amine-phosphinamide bifunctional catalysts has been developed. This reaction afforded Warfarin and its analogs in moderate to excellent yields (up to 99%) and good to excellent enantioselectivities (up to 99% ee).