Steric effects on the mechanism of reaction of nucleophilic substitution of β-substituted alkoxyvinyl trifluoromethyl ketones with four secondary amines
作者:Sergey I. Vdovenko、Igor I. Gerus、Valery P. Kukhar
DOI:10.1002/poc.1152
日期:2007.3
transition state 8). The amine basicity determined the route of the reaction: the higher amine basicity, the higher k3/k2 ratio (a measure of the ‘catalyzed’ route contribution as compared to the ‘uncatalyzed’ process) was. ‘Uncatalyzed’ route predominated for all reactions; however in polar acetonitrile the contribution of the ‘catalyzed’ route was significant for amines with high pKa and small bulk
β-取代的β-烷氧基乙烯基三氟甲基酮的反应动力学R 1 O-CR 2 CH-COCF 3(1a – e)[(1a),R 1 C 2 H 5,R 2 H; (1b),R 1 R 2 CH 3;(1c),R 1 C 2 H 5,R 2 C 6 H 5;(1d),R 1 C 2 H 5,R 2V - p NO 2 C 6 H 4;(1e),R 1 C 2 H 5,R 2 C(CH 3)3 ]与四个脂族胺(2a - d)[(2a),(C 2 H 5)2 NH;(2b),(i -C 3 H 7)2 NH;(2c),(CH 2)5 NH;(2d),O(CH 2在两种非质子传递溶剂(己烷和乙腈)中研究了CH 2)2 NH]。(1a - d)的反应性最低的立体异构体形式是人口最多的(EsZoZ)形式,而在(1e)的反应性更高的立体异构体形式(ZsZoZ)则占主导地位。所研究的反应是通过常见的过渡态形成进行