Structure−Reactivity Correlations in the Dissociative Hydrolysis of 2‘,4‘-Dinitrophenyl 4-Hydroxy-X-benzenesulfonates
作者:Giorgio Cevasco、Sergio Thea
DOI:10.1021/jo961024k
日期:1996.1.1
The hydrolysis reactions of several title esters in water at 60 degrees C follow the rate law k(obs) = (k(a) + k(b)[OH(-)])/(1 + a(H)/K(a)), where K(a) is the ionization constant of the hydroxy group of the ester and k(b) is the second-order rate constant for the S(N)2(S) attack of hydroxide ion on the ionized ester. Hammett and Brønsted correlations are consistent with a previous proposal that the
几种标题酯在60°C的水中的水解反应遵循速率定律k(obs)=(k(a)+ k(b)[OH(-)])/(1 + a(H)/ K( a)),其中K(a)是酯的羟基的电离常数,k(b)是氢氧根离子对离子化酯的S(N)2(S)攻击的二级速率常数。Hammett和Brønsted相关性与先前的建议一致,即与k(a)有关的机制是分离的。发现k(a)值与取代醌的氧化还原平衡常数之间存在异常关系:这一发现进一步支持了与k(a)有关的途径的解离性质。