Detailed Analysis for the Solvolysis of Isopropenyl Chloroformate.
Detailed Analysis for the Solvolysis of Isopropenyl Chloroformate.
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DOI：
10.5155/eurjchem.2.2.130-135.405
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发表时间：
2011-06
期刊：
影响因子：
--
通讯作者：
Kevill DN
中科院分区：
文献类型：
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作者：
D'Souza MJ;Shuman KE;Omondi AO;Kevill DN
使用扩展的Grunwald-Winstein方程分析了氯甲酸异丙烯酯（1）的溶剂分解比速率（包括从文献中获得的那些），涉及溶剂亲核性（S-甲基二苯并噻吩离子）的NT标度与基于1-金刚烷基氯溶剂分解的YCl标度相结合。相似模型方法，使用氯甲酸苯酯溶剂分解进行比较，表明占主导地位的双分子羰基加成机制的溶剂分解1在所有溶剂中，除了97%的1，1，1，3，3，3-六氟-2-丙醇（HFIP）。通过应用扩展的Grunwald-Winstein方程获得的结果的广泛评估导致在大多数溶剂中占主导地位的加成-消除机制的建议，但在97- 70%HFIP和97%2，2，2-三氟乙醇（TFE）中，提出叠加单分子（SN 1）型电离正在做出显着贡献。
The specific rates of solvolysis (including those obtained from the literature) of isopropenyl chloroformate (1) are analyzed using the extended Grunwald-Winstein equation, involving the NT scale of solvent nucleophilicity (S-methyldibenzothiophenium ion) combined with a YCl scale based on 1-adamantyl chloride solvolysis. A similarity model approach, using phenyl chloroformate solvolyses for comparison, indicated a dominant bimolecular carbonyl-addition mechanism for the solvolyses of 1 in all solvents except 97% 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). An extensive evaluation of the outcomes acquired through the application of the extended Grunwald-Winstein equation resulted in the proposal of an addition-elimination mechanism dominating in most of the solvents, but in 97-70% HFIP, and 97% 2,2,2-trifluoroethanol (TFE), it is proposed that a superimposed unimolecular (SN1) type ionization is making a significant contribution.