| 초록 |
Production of enantiopure chemicals is important in view of their broad application as pharmaceuticals, agrochemicals, flavors. Heterogeneous enantioselective catalysis is a promising route for the production of enantiopure compounds because it has many advantages such as product separation, stability and regeneration over homogeneous catalysis. The enantioselective hydrogenation of activated ketones over chirally modified Pt is one of the most successful examples. In this study, we investigated the influence of hydrogen pressure and concentrations of the modifier on the turnover frequency and enantiomeric excess in the asymmetric hydrogenation of ethyl pyruvate over cinchonidine modified Pt/γ-Al2O3. The experiments were carried out in a batch reactor under 1-50 bar hydrogen pressure at room temperature. The increase of hydrogen pressure leads to increase of turnover frequency and decrease of enantiomeric excess. The increase of concentration of cinchonidine results in increase of turnover frequency and enantiomeric excess. However, excess cinchonidine has no influence on the catalytic properties. |
