Stereo-differentiating synthesis of optically active amines over heterogeneous asymmetrically modified catalyst

Stereo-differentiating syntheses of optically active amines were carried out over heterogeneous stereo-differentiating catalyst. Optically active amines are very important intermediate for the production of medicines or agro-chemicals. The combinations of metal-modifier-substrate were surveyed for attaining a high enantio-selectivity. As a result, an 11% ee was attained for the enantio-differentiating hydrogenation of methyl pyruvate over cinchonidine modified Pd catalyst. The mode of differentiation(enantio-differentiation or diastereo-differentiation) could be changed according to the amount of modifier in the reaction media. Substrate-modifier interaction was calculated by a density functional theory for evaluating the stereo-differentiating ability of the modifier. The calculation explained the experimental results of the enantio-differentiating hydrogenation of methyl pyruvate over cinchonidine modified Pt catalyst, but it was difficult to explain the results of the enantio-differentiating hydrogenation of methyl acetoacetate over tartaric acid modified Ni catalyst. Ii is revealed that the inclusion of the metal surface to the calculation is important to elucidate the interaction between the modifier and the substrate, especially to elucidate the enantio-differentiating ability of the modifier.