文献类型：期刊文献

英文题名：Epoxidation of olefins with hydrogen peroxide catalyzed by a reusable lacunary-type phosphotungstate catalyst

作者：Hua Li[1];Qiao YunXiang[1];Li Huan[1];Feng Bo[1];Pan ZhenYan[1];Yu YinYin[1];Zhu WenWen[1];Hou ZhenShan[1]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2011

卷号：54

期号：5

起止页码：769

外文期刊名：SCIENCE CHINA-CHEMISTRY

收录：;EI(收录号：20112414055998);WOS:【SCI-EXPANDED(收录号:WOS:000291057000009)】；

基金：The authors would like to express their thanks for helpful suggestions from Prof. Walter Leitner and assistance from Dr. Nils Theyssen. This work was supported by the National Natural Science Foundation of China (20773037, 21073058).

语种：英文

外文关键词：heteropolyphosphotungstate; lacunary; epoxidation; degradation rate

摘要：Olefins and allylic alcohols have been epoxidized with commercially available hydrogen peroxide (30% H(2)O(2)) using a phase transfer catalyst, composed of cetyltrimethylammonium cations and a lacunary-type phosphotungstate anion [PW(11)O(39)](7-) or the complete Keggin-type heteropolyanion [PW(12)O(40)](3-), under two-phase conditions using ethyl acetate as the solvent. It was found that the lacunary-type catalyst showed higher activity and better recyclability than the complete Keggin-type catalyst under the same reaction conditions. (31)P NMR spectroscopy and solubility measurements for the two catalysts revealed that the [PW(11)O(39)](7-) anion had a much faster degradation rate than the [PW(12)O(40)](3-) anion in an excess of H(2)O(2), which resulted in the formation of more catalytically active species. As a result, the lacunary-type phosphotungstate anion-based catalyst gave a better catalytic performance than the complete Keggin-type anion in ethyl acetate.