对Ni-催化C-H功能化的计算研究:控制氧化加和基路的竞争因素
1Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
Journal of the American Chemical Society
|July 1, 2017
概括
密度功能理论 (DFT) 揭示了催化C-H功能化机制. 基质性质决定了反应是否通过Ni (IV) 中间体或Ni (III) 基路进行,控制了C-C和C-X键的形成.
科学领域:
- 有机金属化学
- 计算化学
- 催化剂
背景情况:
- 催化对于C-H功能化至关重要.
- 了解反应机制是优化催化效率的关键.
研究的目的:
- 研究Ni-催化C-H化,化和硫化的机制.
- 确定控制C-C和C-X键形成途径的因素.
- 在C-H功能化中解释基质控制的反应性和选择性.
主要方法:
- 使用密度函数理论 (DFT) 的计算.
- 对C-H裂变进行协同化-解质化 (CMD) 的分析.
- 评估涉及Ni (IV) 中间体和Ni (III) 基的途径.
主要成果:
- C-H裂变始终通过CMD发生.
- 随后的结合形成取决于合伙伴:对于具有低结合解离能量 (BDE) 的固体阻碍基体,基因通路占主导地位.
- 对于不稳定的基质前体,通过Ni (IV) 介质的氧化添加/减少消除是最优的.
结论:
- 催化C-H功能化的机制取决于基质.
- DFT的洞察力解释了实验观察,如替代剂效应,化学和区域选择性.
- 这项研究为设计高效的C-H功能化反应提供了理论框架.
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