来自易斯-依赖酸的选择性和可逆的化反应的机械洞察力,用于基电友循环反应
Martin Stang1, Robert J Mycka1,2, Suzanne A Blum1
1Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
The Journal of organic chemistry
|October 25, 2023
概括
像BBr3这样的易斯酸表现出可逆的基化,通过受控的电友循环,使得可以进入循环硫zwitterions. 这提供了有价值的有机构建块的可预测合成.
科学领域:
- 有机化学 有机化学
- 有机化学 有机化学
- 合成方法论 合成方法论
背景情况:
- 易斯酸,包括化合物,是有机合成中的关键催化剂.
- 了解反应选择性和动力学和热力学相互作用是控制合成结果的关键.
- 三化物和甲基甲基是具有可调节反应性的多功能试剂.
研究的目的:
- 研究不同 Lewis 酸 (ClBcat,BrBcat,BBr3) 与基的反应选择性.
- 探索核链长度对反应途径的影响.
- 阐明涉及可逆化反应中的动力学和热力学控制.
主要方法:
- 作为易斯酸,利用了B-甲基胆 (ClBcat),B-甲基胆 (BrBcat) 和三化物 (BBr3).
- 采用NMR光谱来监测反应的可逆性.
- 使用二维NMR和单晶X射线衍射来表征动力学和热力学产物.
主要成果:
- 观察到不同的反应选择性:基烯化,电友性循环化或组转移,取决于易斯酸和核友.
- 证明BBr3介导的基化是可逆的,允许访问热力学偏好的循环硫zwitterions.
- 展示了 BrBcat,其反应性介于 ClBcat 和 BBr3.3 之间.
结论:
- 酸易斯酸介导化反应的可逆性是获得替代反应途径的关键因素.
- 通过理解和利用这些可逆反应,可以实现对有机合成的可预测控制.
- 这项工作为利用 Lewis 酸产生复杂的有机构建块提供了基础.
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