摘要
用TiCl_4气固相同晶取代法制得的Ti-ZSM-5作催化剂,研究了以H_2O_2为氧化剂氧化苯乙烯生成环氧苯乙烷的对映选择性,发现生成的环氧苯乙烷主要以R构型为主.考察了反应时间,反应温度,催化剂Ti-ZSM-5以及氧化剂[w(H_2O_2)=30％]的用量等反应条件对苯乙烯环氧化反应对映选择性的影响.结果表明,反应温度是影响环氧化反应对映选择性的重要因素,降低反应温度有利于提高对映选择性(ee),当反应温度≤40℃时,ee值可达100％;而反应时间,催化剂及氧化剂[w(H_2O_2)=30％]用量对环氧化反应的对映选择性几乎没有影响.
In this paper, the enantioselective epoxidation of styrene catalyzed by Ti - ZSM - 5 prepared from TiCl4 gas - solid isomorphous substitution using 30% dilute H2O2 as oxidizing agent, is repoted. It was found that ( R ) - styrene oxide was the main product in the reaction system. At the same time, the effects of reaction conditions such as reaction time, reaction temperature and the amounts of catalyst Ti - ZSM - 5 and 30% dilute H2O2 on the enantioselectivity of styrene epoxidation were also investigated. The results showed that reaction temperature was a major factor for the enantioselective epoxidation of styrene. The ee value increased with the decreasing of reaction temperature distinctly, and reached 100% when reaction temperature was below 40℃. However, reaction time and the amounts of catalyst Ti - ZSM - 5 and 30% dilute H2O2 had essentially no effect on the enantioselectivity.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2000年第11期1322-1326,共5页
Acta Chimica Sinica
