Kinetics and mechanism of the anilinolysis of<i>S</i>-aryl<i>N</i>-arylthiocarbamates in acetonitrile
作者:Dae Dong Sung、Hee Man Jang、Dae Il Jung、Ikchoon Lee
DOI:10.1002/poc.1418
日期:2008.11
values that are consistent for a stepwise mechanism with rate-limiting formation of the zwitterionic tetrahedral intermediate. Signs of cross-interaction constants, ρXY (>0), ρXZ (>0) and ρYZ (<0), are all consistent with a stepwise mechanism. It is concluded that the change of the amine from benzylamines to anilines causes a shift of the aminolysis mechanism from a concerted to a stepwise process. Copyright
研究了S-芳基N-芳基硫代氨基甲酸酯(YC 6 H 4 NH C(O)SC 6 H 4 Z,1)与苯胺在乙腈中的氨解反应。的反应速率更受亲核试剂比所述离去基团的nucleofugality的亲核性的影响,但反应物从给TS用于形成四面体中间体的在有效电荷的改变是离去基团在稍大(β ž从- 0.07至-0.14)比在亲核试剂(β X = 0.04-0.12)。布朗斯台德系数的大小在与限速地形成两性离子四面体中间体的逐步机理一致的值的范围内。交叉相互作用常数的迹象,ρ XY(> 0),ρ XZ(> 0)和ρ YZ(<0),都具有阶梯状机制是一致的。结论是,胺从苄胺变为苯胺导致氨解机理从协同过程转变为逐步过程。版权所有©2008 John Wiley&Sons,Ltd.