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: 《华东理工大学学报(自然科学版)》 2006年第3期313-317,共5页
摘 要: 将天然手性高分子聚合物壳聚糖(CS)负载到S iO2上后,再络合M(Pd、P t、Pu和Ph)金属,制得了多相手性加氢催化剂M-CS-S iO2。在空气氛围下,以异丙醇为氢源,考察了M-CS-S iO2对苯乙酮不对称催化氢转移加氢反应的催化活性。研究了活性金属(Pd、P t、Rh和Ru)、载体(ZSM-5、β、M CM-41、S iO2),及钯的前驱物对多相手性加氢催化剂性能的影响。结果表明:Pd-CS-S iO2对苯乙酮不对称转移加氢反应具有较好的催化加氢性能和对R-1-苯乙醇的对映选择性;Pd的前驱物对Pd-CS-S iO2的催化活性和对映选择性的影响较小;载体对Pd催化剂的催化活性和对映选择性的影响很大;在苯乙酮不对称转移加氢反应中,Pd-CS-β分子筛对R-1-苯乙醇的对映体过量值可达到65.7%。 Natural biopolymer of chitosan was supported on SiO2 ,and then active metal (Pd, Pt ,Ru and Rh)was coordinated with chitosan to obtain a chiral heterogeneous catalyst of M-CS-SiO2. Under air atmosphere condition and isopropanol as H-donor,the chiral catalytic activity of M-CS-SiO2 for the asymmetric transfer hydrogenation of acetophenone was investigated. The effects of active metal M (Pt,Pd,Rh and Ru) ,support (ZSM-5,β-zeolite,MCM-41 and SiO2)and Pd precursor on the performance of chiral M CS-support catalyst were also studied. Results show that Pd-CS-SiO2 catalyst has better chiral catalytic activity to acetophenone and enantioselectivity to(R) 1-phenylethanol. Pd precursor has minor effect on its catalytic activity for the hydrogenation of acetophenone. The supports used affect obviously the performance of M-CS-support catalyst. For the asymmetric transfer hydrogenation of acetophenone with isopropanol used as solvent and H-donor,Pd CS-β zeolite catalyst has better enantioselectivity,over which the enantiomeric excess of (R)-1-phenylethaol reaches to 65.70%