Kinetic Study on the Alkaline Hydrolysis of<i>S</i>,<i>S</i>-Diaryl-<i>N</i>-halosulfilimines
作者:Toshiaki Yoshimura、Eiichi Tsukurimichi、Hiroshi Kita、Hiroshi Fujii、Choichiro Shimasaki
DOI:10.1246/bcsj.63.1764
日期:1990.6
Kinetics for the alkaline hydrolysis of S,S-diaryl-N-bromosulfilimines were carried out in aqueous methanol. The observed pseudo-first-order rate constants were found to give a linear correlation with the concentration of sodium hydroxide, k=k1+k2[NaOH]. The first-order rate constants k1 showed a large negative Hammett ρ value (−2.43) for the substituent effect on the phenyl group, nearly zero activation
S,S-二芳基-N-溴亚硫亚胺的碱性水解动力学在甲醇水溶液中进行。发现观察到的伪一级速率常数与氢氧化钠浓度呈线性相关,k=k1+k2[NaOH]。一级速率常数 k1 显示出较大的负 Hammett ρ 值 (-2.43),用于取代基对苯基的影响,几乎为零的活化熵 (-0.9±13.1 JK-1mol-1) 和相对较大的 m 值 (0.638 ) 对溶剂电离能力 Y 值表明反应过程为 k1 接近 SNl。盐效应、氘溶剂同位素效应和空间效应也符合SNl机理。另一方面,二阶速率常数 k2 显示出较小的 Hammett ρ 值、负的激活熵(-44.0±4.0 JK-1mol-1)、较小的 m 值(0. 153) 和邻位取代基的空间减速表明 k2 的反应类似于 SN2。盐效应和溶剂同位素效应也是相容的...