Anion exchange cycle of catalyst in liquid-liquid phase-transfer catalysis reaction: Novel autocatalysis

作者：Zhao, Qiangqiang; Sun, Jie; Liu, Baojiang; He, Jinxin^*

来源：Chemical Engineering Journal, 2015, 262: 756-765.

DOI：10.1016/j.cej.2014.09.113

• Induction period
• Autocatalysis reaction
• Ion-exchange selectivity coefficient
• Phase-transfer catalysis reaction
• Horner-Wadsworth-Emmons reaction

Novel autocatalytic process under liquid-liquid phase-transfer catalysis (LL-PTC) condition was found, which was induced by the anion exchange of catalyst. Induction period existed in Homer-Wadsworth-Emmons reaction under LL-PTC conditions and was not caused by the equilibrium of reactants or the saturation of the intermediate. Introduction of the more hydrophilic anion to PTC system could increase the initial reaction rate and decrease the induction time, especially for diethyl phosphate anion (another product of the bond-forming reaction, PO-). Furthermore, the generation of ion-pair (PTC+PO-) in the biphasic system was certified by extraction experiments. PTC+PO- showed a higher catalytic activity (more than 2-fold) and a higher distribution coefficient from the interfacial region to the organic phase (2.7-fold) than the initial catalyst. Accordingly, the interfacial mechanism including the instinct catalytic cycle and the autocatalytic cycle was proposed, which were induced by the initial catalyst and PTC+PO-, respectively. Subsequently the dependence of instinct catalytic activity and autocatalytic activity on reaction parameters was compared.

• 出版日期2015-2-15
• 单位东华大学