Reaction mechanism of phase-transfer catalysis initiated by hydroxide ion: Effect of alkalinity
作者:Maw-Ling Wang、Chau-Yun Yang
DOI:10.1016/s0040-4020(99)00204-5
日期:1999.5
added due to dissociation of ArOH and salting out effect. Not only the polarity of organic solvent, but also the Lewis base of the organic solvent affected by the concentration of alkaline compound influences the reaction rate. The dielectric constants and the Lewis base of organic solvents in affecting the solvation are used to explain how the reaction rate is influenced by the solvents. The concentration
在溴化四丁铵(QBr)的催化下,在KOH /有机溶剂两相介质的碱性溶液中进行2,4,6-三溴苯酚(ArOH)和α-溴-邻二甲苯(RBr)的反应。一种奇特的现象,其中观察到反应不会随碱性化合物的浓度单调变化。该结果来自以下事实:活性中间体ArOQ的浓度受ArOH的离解和盐析作用而添加的碱性化合物的浓度影响。不仅有机溶剂的极性,而且受碱性化合物浓度影响的有机溶剂的路易斯碱也会影响反应速率。影响溶剂化的介电常数和有机溶剂的路易斯碱用于解释反应速率如何受溶剂影响。在整个反应过程中,2,4,6-三溴苯氧基四丁基铵(ArOQ)的浓度保持恒定。