期刊
NEW JOURNAL OF CHEMISTRY
卷 32, 期 2, 页码 283-289出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/b710444h
关键词
-
Ionic liquid (IL), such as 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), as an activator for the epoxidation of a wide variety of olefins with H2O2 catalyzed by Keggin polyoxometalate [bmim](3)PW12O40 has been demonstrated. Use of IL results both in significant enhancement of TOF and selectivity for olefin epoxidation compared to that of traditional organic solvents, e. g. 289 times TOF and 1.3 times selectivity as found in CH2Cl2 for the epoxidation of cis-cyclooctene. The kinetic P-31 NMR spectra uncover that the active peroxotungstate [PO4{W(O)(O)(2)}(4)](3-) (Venturello complex), contributing to the epoxidation, can be readily generated in the presence of [bmim][PF6]. Furthermore, the counterion such as PF6- and [(CF3SO2)(2)N](-) is evidenced to play a crucial role in the epoxidation of olefin. BF4- as counterion, instead of PF6-, is found to reduce TOF and selectivity for cis-cyclooctene epoxidation dramatically from 289 to less than 1 and from 99% to 12%, respectively.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据