A homodinuclear Co2/aminophenol sulfonamide complex has been developed for the asymmetric Michael reaction of β-ketoesters with nitroolefins. This procedure is capable of tolerating a wide range of substrates and excellent results (up to 99% yield, >99 : 1 dr and 98% ee) can also be obtained. Moreover, the reaction could be carried out on a 50 mmol scale without any decrease in the enantioselectivity and reactivity. On the basis of the results of mechanistic studies, we proposed that the Co2/2a complex would be the active species and a possible catalytic cycle was described.

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.