Enantioselective hydrogenation of isophorone and kinetic resolution of 3,3,5-trimethylcyclohexanone over Pd catalysts in the presence of (S)-proline

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• 作者：Shuang Li ; Ensheng Zhan ; Yong Li ; Yide Xu ; Wenjie Shen
• 关键词：Isophorone ; TMCH ; (S)-Proline ; Enantioselective hydrogenation ; Kinetic resolution
• 刊名：Catalysis Today
• 出版年：2008
• 出版时间：29 February 2008
• 年：2008
• 卷：131
• 期：1-4
• 页码：347-352
• 全文大小：569 K

文摘

Enantioselective hydrogenation of isophorone and kinetic resolution of 3,3,5-trimethylcyclohexanone (TMCH) over Pd catalysts in the presence of (S)-proline revealed that the enantioselectivity for hydrogenation of isophorone was mainly originated from the kinetic resolution of TMCH. The rapid hydrogenation of isophorone primarily yielded racemic TMCH, and the followed kinetic resolution consumed the (R)-TMCH enantiomer, leaving the (S)-TMCH enantiomer in excess. The kinetic resolution of racemic TMCH is closely related to the acidic/basic properties of the support, and the addition of K₂CO₃ to Al₂O₃ provided more enantio-differentiating environment through the enhanced adsorption of (S)-proline on the catalyst surface. As a result, the Pd/Al₂O₃-K₂CO₃ catalyst with finely dispersed Pd particles and enhanced adsorption of (S)-proline gave very high enantioselectivities (e.e. value up to 98 % ) for the enantioselective hydrogenation of isophorone.