催化剂用于C-H激活:实验/理论研究确定了控制氧化和脱路径之间的切换的立体电子因子
Jonathan F Hull1, David Balcells, Effiette L O Sauer
1Chemistry Department, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, USA.
Journal of the American Chemical Society
|May 21, 2010
概括
合成催化剂可以通过脱和基化激活竞争性C-H键. 这些反应共有一个共同的初始步骤,立体电子因素决定了结果,为酶机制提供了洞察力.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 计算化学计算化学
背景情况:
- 在合成化学和生物过程中,C-H键激活至关重要.
- 色氨酸复合物是已知的氧化反应的催化剂.
- 了解相互竞争的反应途径对于催化剂设计至关重要.
研究的目的:
- 用合成催化剂研究竞争性C-H键激活 (脱和化).
- 通过实验和计算方法阐明反应机制.
- 探索催化剂结构和基质定向在指导反应路径中的作用.
主要方法:
- 使用合成催化剂与各种基质,包括9,10-二二 (DHP) 的实验研究.
- 产品分析,以确定脱 (氨酸,氨酸9,10-氧化物) 和基化 (氨酸-9,10-) 产品.
- 密度函数理论 (DFT) 计算以建模活性物种和反应中间体.
主要成果:
- 催化剂促进了DPH的脱和氧化.
- DFT计算揭示了一个常见的初始H抽象步骤的Mn oxo物种.
- 这两种途径都表现出较低和相似的能量障碍,导致产品混合;立体电子因素影响选择性.
结论:
- 合成催化剂[Mn ((O) ((tpp)) ((Cl)) ]可以调解竞争的C-H激活通路.
- 反应结果对基质相对于催化剂活性部位的方向敏感.
- 这些发现提供了关于酶如何在基酶和脱酶功能之间切换的见解.
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