奎宁修饰型Pt/Al_2O_3催化丙酮酸乙酯不对称加氢反应:乙酸溶剂与甲苯溶剂的比较  

Asymmetric Hydrogenation of Ethyl Pyruvate over Pt-alumina Modified by Quinine:Comparison of the Solvent of Acetic acid and Toluene

作　　者：陶国忠[1] 谢宝赓[1] 石铭亮[1] 

机构地区：[1]华东理工大学大型工业反应器工程教育部工程研究中心,上海200237

出　　处：《分子催化》2009年第6期523-528,共6页Journal of Molecular Catalysis(China)

基　　金：上海市科委纳米专项基金资助(0552nm022)

摘　　要：采用奎宁修饰型Pt/A l2O3作为加氢催化剂在常温常压下比较了乙酸和甲苯溶剂中丙酮酸乙酯的不对称加氢与一般的加氢反应的反应结果;研究了反应对映选择性与底物转化率的关系、丙酮酸乙酯用量对产物对映选择性的影响、三乙胺的作用以及乙酸-甲苯混合溶剂的使用.实验结果表明,乙酸作为反应溶剂的性能优于甲苯且溶剂化作用强于甲苯;两种溶剂中的不对称加氢反应均存在初始过渡期,以乙酸为溶剂时,催化反应速度较快;在乙酸溶剂中底物用量对产物对映纯度影响不大,在甲苯溶剂中底物用量具有最佳值;在乙酸溶剂中加入三乙胺能显著提高反应的对映异构体选择性而在甲苯溶剂中则没有促进作用.Using acetic acid and toluene as reaction solvents, the results of asymmetric and general hydrogenation of ethyl pyruvate over Pt alumina catalyst modified by quinine were compared under room temperature and atmospheric pressure ; the dependence of reaction enantioselectivity on substrate conversion, effect of substrate amount on product enantioselectivity, role of triethylamine in two solvents and the usage of acetic acid toluene component solvent were investigated. Our research suggests that the performance and solvation of acetic acid as a solvent for asymmetric hydrogenation outperforms toluene; there exists an initial transient period during the asymmetric hydrogenation of ethyl pyruvate in both solvents and the catalytic reaction speed in acetic acid is faster than toluene; the amount of substrate almost have no influence on product enantioseleetivity in acetic acid while there is an optimum value in toluene; the addition of triethylamine increases the reaction enantioseleetivity significantly in acetic acid but has no promotional effect in toluene.

关 键 词：不对称加氢 PT/AL2O3 丙酮酸乙酯 奎宁修饰 溶剂效应 

分 类 号：O643.32[理学—物理化学]