从和离子直接转移和离子组到基的观测
Scott E Denmark1, William R Collins, Matthew D Cullen
1Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA. sdenmark@illinois.edu
Journal of the American Chemical Society
|February 21, 2009
概括
硫和离子以立体特异的方式从三环环转移到基. 转移是瞬间发生的,而硫转移是不同的,表明这些硫和离子的稳定性不同.
科学领域:
- 有机硫化学 有机硫化学
- 有机化学化学 有机化学
- 反应机制 反应机制
背景情况:
- 硫和离子是反应性中间体.
- 三个成员的环状物种,称为 - - 离子,是前体.
- 了解它们的转移反应是合成应用的关键.
研究的目的:
- 为了研究硫和离子的立体特异转移.
- 为了比较和离子的反应性和稳定性.
- 探索替代剂对转移能力和离子稳定性的影响.
主要方法:
- 使用白银六四胺酸生成和六二胺酸.
- 使用NMR光谱 (1H, 13C, 77Se) 进行生成离子的表征.
- 在不同温度下研究与未激活基的离子转移反应.
- 均衡测量以确定离子的相对稳定性.
主要成果:
- 离子表现出可变的转移能力;S-phenylthiiranium转移缓慢,而S-methylthiiranium没有转移.
- 离子 (Se-phenyl和Se-butyl) 在低温 (-70°C) 时瞬间转移了部分.
- 建立了1-phenylseleniranium离子的相对稳定性顺序: cis-tetramethylene < trans-2,3-dipropyl ≈ trans-2,3-diisopropyl < cis-hexamethylene. 这就是为什么它是如此.
结论:
- 硫和离子表现出不同的转移行为和稳定性.
- 与离子相比,离子通常更具反应性,并且很容易转移部分.
- 该研究提供了有关这些重要的硫和中间体稳定性和反应性因素的见解.
相关概念视频
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