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轴系协调如何调节铁-氨酸-的电子结构和C-H氨基反应活性?

Mayank Mahajan¹, Bhaskar Mondal¹

¹School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh 175075, India.

|December 29, 2023

概括

铁-氨酸-亚烯复合体中的弱轴协调增强了C-H氨化反应性. 这项研究揭示了不同的轴联体如何调整电子结构和反应性,通过五重旋转状态促进有效的氧化.

科学领域:

计算化学是一种计算化学.
有机金属化学有机金属化学
反应机制的反应机制

背景情况:

铁氨酸复合物是氧化反应中的关键催化剂.
了解Fe-nitrene中间体的电子结构是控制反应性的关键.
轴系协调显著影响金属酸的特性.

研究的目的:

为了研究Fe-porphyrin-nitrene中间体的电子结构,具有多种不同的轴联体.
为了将电子结构与分子内C-H氨化反应性相关联.
阐明轴心协调强度在调节反应性的作用.

主要方法:

多配置自一致场 (CASSCF) 的计算.
电子相关性 N-电子价值扰动理论 (NEVPT2) 的电子相关性.
混合密度功能理论 (DFT-B3LYP) 用于反应性研究.
电子结构 (imidyl与imido-like特性) 和旋转状态的分析.

主要成果:

确定了两个不同的电子结构:"imidyl" (较强的轴协调) 和"imido-like" (较弱的轴协调).
较弱的轴系协调可以更轻松地进入低的五重奏状态,从而实现三重奏-五重奏的反应性.
较强的轴系协调导致三重仅原子转移 (HAT) 反应性.

结论:

轴系协调强度极为关键地调节了Fe-porphyrin-nitrene中间体的电子结构和旋转状态的可访问性.
较弱的轴坐标通过五重旋转状态促进更有效的C-H氧化.
这为设计用于选择性C-H功能化的催化剂提供了见解.

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