六甲基伊尔迪西拉齐德/三乙烯胺介导的基因溶解:显著的速度加速源于基于二聚体的机制
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA.
Journal of the American Chemical Society
|April 3, 2003
概括
六甲基二氧化 (LiHMDS) 通过循环二聚体中间体调解2 - 甲基环松的化. 添加三乙烯胺可通过一种新型的四重复合物显著加快这一过程.
科学领域:
- 有机化学 有机化学
- 反应机制 反应机制
- 频谱学是一种光谱学.
背景情况:
- 化是有机化学的一个基本反应,对于C-C键形成至关重要.
- 六甲基西拉化物 (LiHMDS) 是一种强大的非核基,广泛用于有机合成.
- 了解基质介导乙醇化的精确机制是控制反应性和选择性的关键.
研究的目的:
- 为了阐明由LiHMDS调解的2-甲基环松溶解的机制.
- 调查三乙烯胺 (Et3N) 在LiHMDS介导的乙醇化中的结构和机制作用.
- 确定在氨基酸的存在下观察到的速度加速的因素.
主要方法:
- 使用结构和速率调查的机制研究.
- 现场红外 (IR) 光谱仪用于实时反应监测.
- 核磁共振 (NMR) 光谱用于中介物质的结构阐明.
主要成果:
- 在烯中进行的结构研究揭示了LiHMDS和的循环二元复合体: (TMS2NLi) 2 ().
- 在现场红外光谱学表明,以二聚体为基础的过渡结构进行化.
- 在三乙胺 (Et3N) 存在的情况下进行的NMR研究表明,四基复合物的定量形成: (TMS2NLi) 2 (((Et3N) (((基),导致速度加速>3000倍.
结论:
- 通过LiHMDS对2-甲基环松的化过程通过二度介质进行.
- 三乙胺作为易斯基,形成一个四重复合物,显著提高化率.
- 这些发现为聚合物和氨基添加剂在胺介导反应中的作用提供了关键的见解.
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