Highly Enantioselective Michael Addition of Dithiomalonates to Nitroolefins Catalyzed by New Bifunctional Chiral Thioureas

We report a highly efficient asymmetric Michael addition of dithiomalonates to trans-nitroolefins catalyzed by versatile cinchona-based bifunctional thioureas, which provides the corresponding adducts in high yields (up to 92%) and with excellent enantioselectivities (up to 99% ee) under mild conditions. Replacement of the catalyst with its pseudo-enantiomer gives the Michael adducts with opposite configuration in similar yields and enantioselectivities.