作　　者： ; ; ; ; ;

机构地区： 华东理工大学化学与分子工程学院结构可控先进功能材料及其制备教育部重点实验室

出　　处： 《应用化学》 2006年第1期42-47,共6页

摘　　要： 将天然手性高分子聚合物壳聚糖负载到二氧化硅上,再负载活性金属制得了多相手性加氢催化剂 (M-CS-SiO2),用元素分析、FT-IR和XRD测试技术对催化剂进行了表征,并在空气氛围下,考察了对苯乙酮不对称氢转移加氢反应的催化活性和产物的对映选择性。结果表明,活性金属组分对手性催化剂的性能有较大的影响,在研究的Pd、Pt、Rh和Ru催化剂中,Pd催化剂具有最好的催化活性和R-1-苯乙醇的对映选择性, 不同的Pd前驱物对催化剂的性能影响较小。在Pd-CS-SiO2催化的苯乙酮不对称加氢反应中,氢源和反应温度对催化剂的活性和产物的对映选择性影响较大,甲酸铵和甲酸钠是优良的氢源。以甲酸铵为氢源时,少量水的存在对苯乙酮不对称转移加氢反应有抑制作用;以甲酸钠为氢源时,添加质量分数为5％的水时,产物的对映选择性可增加8．4％。在80℃反应时,产物R-1-苯乙醇的对映选择性达到69％。 A chiral heterogeneous hydrogenation catalyst（ M-CS-SiO2 ） was prepared by supporting transition metal on natural macromolecular biopolymer of chitosan covering on silicon dioxide, and characterized with elemental analysis, FT-IR and XRD. The catalytic performance of the chiral catalyst was investigated for the asymmetric transfer hydrogenation of acetophenone to R（S）-1-phenyl ethanol in ambient condition. The results indicate that among the chiral M-CS-SiO2 （M = Pd, Pt, Rh and Ru） catalysts prepared, the Pd-CS-SiO2 catalyst shows the best catalytic activity and enantioselectivity to R-l-phenyl ethanol, and the palladium precursor affects its catalytic performance very little. In the asymmetric transfer hydrogenation of acetophenone catalyzed with Pd-CS-SiO2, the catalytic activity and the enantioselectivity are greatly influenced by the sort of H-donor used and reaction temperature. Ammonium formate and sodium formate are the suitable hydrogen donors. If there is some water in the solvent, the asymmetric transfer hydrogenation of acetophenone will be deteriorated as ammonium formate is used as H-donor; when sodium formate is used as H-donor, the presence of 5% water in the solvent can increase 8.4% enantiomeric excess. When ammonium formate was used as hydrogen donor and the asymmetric transfer hydrogenation of acetophenone was performed at 80 %, the enantiomeric excess of R-1-phenylethanol reached to 69%.

关 键 词： 苯乙酮 手性加氢 氢转移 壳聚糖 多相催化加氢

领　　域： [理学] [理学]