Asymmetric Hydrogenation with Modified Raney Nickel. II. Studies on Modified Hydrogenation Catalyst. III

Abstract

Abstract 1) The asymmetric R-Ni catalysts were prepared by the treatment of R-Ni with various asymmetric compounds, and the asymmetric activity of a catalyst was measured by the hydrogenation of methyl acetoacetate 2) Optical rotatory direction and power of the reduced product was affected both by the configuration and molecular size of amino acid which was used as modifying reagent. 3) The asymmetric activity of catalysts treated with N-substituted amino acids, N-acyl, N-dimethyl and N-cyanoethyl derivatives of Glu and Asp, were much less than the activity of the catalyst treated with the corresponding amino acids. 4) The asymmetric activity of the catalyst treated with d-tartaric acid and l-malic acid was tested at various conditions. The asymmetric yield in the hydrogenation of methyl acetoacetate in the presence of the catalyst treated with d-tartaric acid solution of pH 5.1∼5.2 at 100°C was about 45 percent.