离去基团、非离去基团及中间体性质对取代苯甲酸苯酯氨解反应的影响  

Influence of the Properties of Leaving Group,Non-leaving Group and Intermediate on the Aminolysis Reaction of Substituted Phenyl Benzoates

作　　者：袁华[1] 曹晨忠[1] 

机构地区：[1]理论化学与分子模拟教育部重点实验室分子构效关系湖南省普通高校重点实验室湖南科技大学化学化工学院,湘潭411201

出　　处：《化学通报》2009年第6期515-515,共1页Chemistry

摘　　要：X-取代苯甲酸Y-取代苯基酯(X-C6H4COOC6H4-Y)的氨解反应是一个亲核加成-消除过程。为定量评价Um等对非离去基团(X-C6H4-)、离去基团(Y-C6H4O-)及中间体(T±)的性质对氨解反应速率(kN)影响的研究结果,分别用取代基X的Hammett常数σX、Y-C6H4OH的pKa和取代基X、Y的极化效应指数PEI表征上述结构因素,并用其对logkN建立多元线性回归模型,得到了良好的相关结果。进一步分析得出,Y-C6H4OH的pKa对logkN的影响最大(贡献率为90.46%),而取代基X的Hammett常数σX影响最小。The aminolysis reaction of Y-substituted phenyl X-substituted benzoates （X-C6H4COOC6H4-Y） is a nucleophilic addition-elimination process. In order to quantitatively evaluate the influence of structural factors of nonleaving group （X-C6H4-）, leaving group （Y-C6H4O-） and intermediate （T^±） on the apparent second-order rate constants （kN） of aminolysis of the title compounds reported by Um etc, Hammett constant σx of substituent X, pKa of Y-C6H4OH and polarizability effect index （PEI） of substituents X and Y were used to characterize the above mentioned structural information and build multiple linear regression model against logkN. Good correlation results had been obtained. Further investigation indicated that the pKa of Y-C6H4OH has the most important effect on logkN （its contribution percentage is 90.46% ）, while Hammett constant Zx of substituent X has the least influence on logkN.

关 键 词：取代苯甲酸苯酯 氨解 反应速率 电子效应 极化效应指数 

分 类 号：O621.25[理学—有机化学]