Novel carbohydrate-based thioureas as organocatalysts for asymmetric michael addition of 1,3-dicarbonyl compounds to nitroolefins

Abstract A series of novel carbohydrate-derived thioureas were synthesized and examined as catalysts for the asymmetric Michael addition of symmetrical 1,3-dicarbonyl compounds, including dimethyl malonate, to several trans-β-nitrostyrenes. High enantioselectivities (up to 94% ee) as well as high yields (up to 98%) were attained using a bifunctional organocatalyst bearing a cinchona-based alkaloid unit.