作者:Kwang-Ting Liu、Mann-Yan Kuo
DOI:10.1016/s0040-4020(01)85982-2
日期:1988.1
Solvolysis of 2-aryl-3,3-dimethyl-2-butyl p-nitrobenzoates (4a-4d) and the 1,1,1-trideuterio derivatives (5a, 5b, 5c) in HFIP exhibited a high kinetic isotope effect, k(CH3)/k(CD3) = 1.90 at 60°C for the deactivating substrates 4c vs 5c. This effect decreased significantly with increasing electron releasing of the substituent on the aryl ring. Hammett-Brown treatment of the rate data for 4 yielded
对硝基苯甲酸2-芳基-3,3-二甲基-2-丁酯(4a-4d)和1,1,1-三苯并呋喃衍生物(5a,5b,5c)的溶剂分解显示出高的动力学同位素效应,k对于失活衬底4c对5c,在60℃下的(CH 3)/ k(CD 3)= 1.90。随着芳基环上取代基的电子释放增加,该效应显着降低。Hammett-Brown处理4个速率数据产生了极好的线性关系(r = 0.999),ϱ + = -3.48。显然,α-甲基对阳离子过渡态稳定的贡献不是恒定的。讨论了线性自由能关系中的近似值。