化学学报 ›› 2003, Vol. 61 ›› Issue (6): 922-925. 上一篇    下一篇

研究论文

TiO_2负载的纳米铑簇合物催化丙酮酸乙酯不对称氢化反应的研究

熊伟;黄裕林;马红霞;陈华;黎耀忠;李蕾蕾;程溥明;李贤均   

  1. 四川大学化学学院
  • 发布日期:2003-06-15

Studies on the Asymmetric Hydrogenation of Ethyl Pyruvate Catalyzed by TiO_2 Supported Rhodium Nanocluster

Xiong Wei;Huang Yulin;Ma Hongxia;Chen Hua;Li Yaozhong;Li Leilei;Cheng Puming;Li Xianjun   

  1. Department of Chemistry, Sichuan University
  • Published:2003-06-15

研究了辛可尼定作手性修饰剂修饰的负载型纳米铑簇保物催化剂(0.5% Rh/PVP-TiO_2)催化丙酮酸乙酯不对称氧化反应,在该反应中手性修饰剂辛可尼 定不仅具有对产物生成的手性诱导作用,而且对反应具有明显加速作用;在优化反 应条件后,反应的TOF和对映选择性分别可以达到58.0 min~(-1)和61.9% e.e.。

关键词: 丙酮酸乙酯, 氢化, 不对称, 辛可尼定, 氧化

In the asymmetxic hydrogenation of ethyl pyruvate catalyzed by 0.5% Rh/PVP-TiO_2, the chiral modifier cinchonidine not only induces the enantioselectivity, but also accelerates the reaction rate greatly. A promotion effect of TiO_2 for the asymmetric hydrogenation is observed, when the modified rhodium nanoclusters are supported on TiO_2. The results show that TOF increase from 15.7 to 58.6 min~(-1) and e.e. values of R( + )-ethyl lactate increase from 42.2% to 60.0% in the hydrogenation of ethyl pyruvate. This suggests that TiO2 is favourable for the dispersion of Rh/PVP and its stabilization on the support surface. Under the optimum conditions: 298 K, p_(H_2) =6.0 MPa, 4. 3*10~(-3) mol/L cinchonidine in THF, ethyl pyruvate/rhodium = 942 (molar ratio), TOF and e.e. value are 58.6 min~(-1) and 61.9%, respectively.

Key words: ethyl pyruvate, HYDROGENATION, ASYMMETRY, cinchonidine, OXIDATION

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