Silicon phosphorus analogies. Fluoride activation of nucleophilic displacement at the tetrahedral phosphorus: an example of nucleophilic assistance to nucleophilic substitution. 3
Analogies between silicon and phosphorus stereochemistry—II
作者:R.J.P. Corriu、J.P. Dutheil、G. Lanneau
DOI:10.1016/s0040-4020(01)98898-2
日期:1981.1
The stereochemistry of reactions of cyclic halogenophosphates with a representative series of p-substituted aryloxides emphasizes the relative influence of the attacking anion. For a given leaving group, the stereochemistry depends essentially upon the electronic character of the p-substituent and the ion-pair dissociation of the nucleophile. Both stereochemical and kinetic data rule out a cation-assisted
环状卤代磷酸盐与代表性的一系列对位取代的芳氧基的反应的立体化学强调了进攻阴离子的相对影响。对于给定的离去基团,立体化学基本上取决于对位取代基的电子特性和亲核试剂的离子对解离。立体化学和动力学数据都排除了阳离子辅助机理来解释在磷处的保留。同时,S N 2(P)和S N之间的比较图2(Si)提出了两个系列中类似的机制。保留和/或反转是相似能量的两个竞争反应的结果。立体化学是由影响亲核试剂产生不同几何形状的两种初始中间体的方法决定的。
Methanolysis of a phosphate triester: a change in mechanism with acidity