Enantioselective Michael addition using 4(3H)-pyrimidinone

The framework of 4-pyrimidinones is prevalent in biologically and medicinally important molecules. Here we report that chiral N-substituted 4-pyrimidinones were prepared by an enantioselective, organocatalytic aza-Michael addition of 4(3H)-pyrimidinone (4-hydroxypyrimidine) to α,β-unsaturated 1,4-dicarbonyl compounds for the first time. The reactions were optimized by the choice of solvents, screening Cinchona alkaloid-based bifunctional catalysts, and Michael acceptors to achieve good yields and enantioselectivities.