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导向外部电场的甲基转移反应的催化:金酸连接器是无辜的吗?

Rajeev Ramanan¹, David Danovich¹, Debasish Mandal²

¹Institute of Chemistry , The Hebrew University of Jerusalem , Jerusalem , 91904 , Israel.

Journal of the American Chemical Society

|March 8, 2018

概括

导向外部电场 (OEEF) 可以控制像门舒金反应这样的化学反应. 逆转电场

科学领域:

物理化学
计算化学
化学反应动力学

背景情况:

外部电场 (EEF) 越来越被认为是控制化学反应的强大工具.
门舒特金反应是一种基本的双分子反应,形成四级盐,作为研究反应机制的模型系统.
了解外部刺激如何影响反应途径对于设计新型合成方法至关重要.

研究的目的:

研究导向外部电场 (OEEF) 对门舒特金反应的催化和抑制作用.
探索EEF诱导反应控制的理论基础,包括遵守已确定的化学原则.
检查实验性输送系统,如黄金-硫酸盐连接剂对EEF介导反应的影响,并预测潜在的机械转移.

主要方法:

在OEEF的影响下,替代和甲基化物之间的Menshutkin反应的理论分析.
计算建模研究电场方向和强度对反应能量和路径的作用.
将黄金硫酸盐连接剂纳入理论模型,以评估它们对反应机制和EEF反应的影响.

主要成果:

OEEFs可以通过简单地改变N---C---I反应轴上的场方向来催化或抑制Menshutkin反应.
催化和抑制现象与贝尔-埃文斯-波兰尼原理一致,即使对于与反应轴不完全一致的场所,也预测了显著的催化.
金酸连接器不是惰性的,可以诱导模仿OEEF效应的局部电场,可能会通过高电场强度的电荷转移状态导致机械交叉.

结论:

OEEF提供了一种通用而精确的控制门舒特金反应的方法,可实现按需的催化或抑制.
这项研究预测,EEFs也可以驱动前侧核友的移位,挑战传统的立体化学范式,如沃尔登反转.
涉及链接分子的实验考量至关重要,因为它们可以积极参与反应机制并调解EEF效应,包括潜在的机制转移.

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