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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 of the X-substituted benzoic acid Y-substituted phenyl ester (X-C6H4COOC6H4-Y) is a nucleophilic addition-elimination process. In order to quantitatively evaluate the effect of Um and other factors on the rate of amidation reaction (kN) of non-leaving groups (X-C6H4-), leaving groups (Y-C6H4O-) and intermediates (T ±) The above structural factors were characterized by the Hammett constant σX of the substituent X, the pKa of Y-C6H4OH and the polarization effect index PEI of the substituents X and Y, respectively. Multiple linear regression models were established for logkN, and good correlation results were obtained. Further analysis showed that the pKa of Y-C6H4OH had the greatest effect on logkN (contribution rate of 90.46%), while the Hammett constant σX of substituent X had the least effect.