Bifunctional chiral urea catalyzed highly enantioselective Michael addition of cyclic 1,3-dicarbonyl compounds to 2-enoylpyridines

A highly efficient cinchona alkaloid based bifunctional urea catalyzed enantioselective conjugate addition of cyclic 1,3-dicarbonyl compounds to a range of β-substituted 2-enoylpyridines has been developed. Chiral 2,4-diaryl substituted 1,4-dihydropyridines could easily be accessible from these Michael adducts. Significantly, this asymmetric methodology could afford both enantiomers of the products with the same level of enantioselectivities by using pseudoenantiomeric catalysts with up to 98% ee and in excellent yields.