| 초록 |
The growing demand for enantiomerically pure compounds in fine chemical industries has stimulated an interest in asymmetric catalysis. Heterogeneous enantioselective catalysis is a fascinating method to produce the enantiopure chemicals. Adsorption of chiral organic modifiers on metal surface has been widely used for chiral modification. Here, we report catalytic performances of silica-supported Pt catalysts for asymmetric hydrogenation of α-ketoester. The Pt catalysts were supported AEROSIL SiO2, MCM-41, SBA-15, KIT-6, and MCF via a facile impregnation. They were characterized by XRD, TEM, N2 physisorption and CO chemisorption techniques. Among the Pt catalysts, cinchonidine-modified Pt/MCF catalyst with the larges pore of 23 nm, showed the highest enantiomeric excess and conversion under 1 bar of H2 pressure. The Pt/MCF catalyst exhibited no distinct loss in activity and enantioselectivity for 10 cycles of reactions. These results indicate that Pt/MCF catalyst is the most promising catalyst in this reaction. It implies that the structure of mesoporous silica supports can play a vital role in controlling the enantioselectivity. |
