Asymmetric organocatalytic Michael addition of Meldrum's acid to nitroalkenes: probing the mechanism of bifunctional thiourea organocatalysts

摘要

The asymmetric Michael addition of Meldrum’s acid to nitroalkenes was studied using a novel type of Cinchona alkaloid-based bifunctional thiourea organocatalyst. The functionality of the thiourea catalysts was also probed by preparing and testing thiourea-N-methylated analogues of the well-known bis-(3,5-trifluoromethyl)phenyl-substituted catalyst.