Rationalization of the conflicting effects of hydrogen bond donor solvent on nucleophilic aromatic substitution reactions in non-polar aprotic solvent: reactions of phenyl 2,4,6-trinitrophenyl ether with primary and secondary amines in benzene–methanol mixtures
作者:Olayinka Banjoko、Ibitola A. Babatunde
DOI:10.1016/j.tet.2004.03.079
日期:2004.5
kinetics of the reactions of phenyl 2,4,6-trinitrophenyl ether with piperidine and cyclohexylamine respectively were studied at different amine concentrations in benzene. The reaction of cyclohexylamine was not base-catalysed while that of piperidine was catalysed by one molecule of the nucleophilic amine. Addition of small amounts of hydrogen-bond donor solvent, methanol to the benzene medium of the
在苯中不同胺浓度下,分别研究了苯基2,4,6-三硝基苯基醚与哌啶和环己胺的反应动力学。环己胺的反应不是碱催化的,而哌啶的反应是由一分子的亲核胺催化的。在反应的苯介质中添加少量的氢键供体溶剂,甲醇会产生不同的效果-速率降低,然后是速率升高,而另一种是连续速率降低。将这些效果与苯胺(先前已研究)的效果进行了比较,后者观察到了连续速率的增加。根据胺-溶剂相互作用对胺的亲核性的影响以及除其他一些通过产生产物的环状过渡态起作用的因素外,对结果进行了合理化。从合理化中可以明显看出,亲核芳族取代反应中“二聚体亲核体”的想法是错误的。