Nucleophilic substitution at sulphonyl sulphur. Part 2. Hydrolysis and alcoholysis of aromatic sulphonyl chlorides
作者:Francesco P. Ballistreri、Alfio Cantone、Emanuele Maccarone、Gaetano A. Tomaselli、Mario Tripolone
DOI:10.1039/p29810000438
日期:——
sulphonyl chlorides. In this case the negative δ value, which is related to the steric parameter, is consistent with steric acceleration due to relief of strain in the transition state. Alcoholysis rates of substituted thiophen-2-sulphonyl chlorides (5-CH3, 5-Cl, 4-NO2, and 5-NO2) have been also measured in order to compare the substituent effects with those already observed for hydrolysis. The data are
已经测量了呋喃-2-和-3-,噻吩-2-和-3-以及苯磺酰氯的水解,甲醇分解和乙醇分解的动力学。发现与杂环的Taftσ*值具有公平的相关性;通过应用两参数(极性和空间)Taft-Pavelich方程,可以观察到更令人满意的趋势,特别是对于水解反应,包括脂肪族磺酰氯的数据。在这种情况下,与空间参数有关的负δ值与由于过渡状态中的应变释放而引起的空间加速度一致。取代的噻吩-2-磺酰氯(5-CH的醇解率3,5-氯,4-NO 2和5-NO 2为了将取代基效果与已经观察到的水解效果进行比较,还测量了()。数据与先前的发现相符,即发生了S N 2型机理,在水解和醇解反应中发生了向S N 1过程(更弱的过渡状态)或S A N过程(更紧密的过渡状态)的转变,分别。