Effect of micro and bulk solvation on the mechanism of nucleophilic substitution at sulfur in disulfides
Effect of micro and bulk solvation on the mechanism of nucleophilic substitution at sulfur in disulfides
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DOI：
10.1021/jp035407f
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发表时间：
2003-10-02
影响因子：
2.9
通讯作者：
Bachrach, SM
中科院分区：
文献类型：
--
作者：
Hayes, JM;Bachrach, SM
对具有明确水表示的二硫化物中硫的亲核取代的溶液相机制的计算研究表明，该途径依赖于被攻击硫的取代基。采用B3LYP/6-31+G*优化了含1 ~ 4个明确水分子的硫代酸-二硫交换反应原型，并利用B3LYP/6-31+G*和极化连续介质模型（PCM）进行了单点自由能计算。当被攻击的硫带氢时，溶液相机制为加成-消除机制，而当硫取代基为甲基时，预测为S(N)2机制。
Computational studies of the solution-phase mechanism of nucleophilic substitution at sulfur in disulfides with explicit water representation indicate that the pathway is dependent on the substituent on the sulfur under attack. B3LYP/6-31+G* optimizations for prototype thiolate-disulfide exchange reactions were performed including one to four explicit water molecules, followed by single-point free energy calculations with B3LYP/ 6-31+G* and the polarized continuum model (PCM). The solution-phase mechanism is the addition-elimination mechanism when the sulfur under attack bears a hydrogen, while the S(N)2 mechanism is predicted when the sulfur substituent is a methyl group.