Catalytic enantioselective Henry reaction of α-keto esters, 2-acylpyridines and 2-acylpyridine N-oxides

摘要

A pre-prepared Ni–PyBisulidine complex has been developed for the catalytic asymmetric Henry reaction of α-keto esters, 2-acylpyridines and 2-acylpyridine N -oxides. The corresponding β-nitro-α-hydroxy esters were obtained in good to excellent yields (up to 99%) with a high enantiomeric excess (ee) (up to 94%) with a catalyst loading of 1–2 mol%. The desired products of 2-acylpyridines and 2-acylpyridine N -oxides, which were simple methyl ketones, were obtained in medium to excellent yields (up to 94%) with medium to good ee (up to 86%) by using 2 mol% of catalyst.