通过Pd (OAc) 催化的有氧化C-H的光谱和动态表征
Jonathan N Jaworski1, Caitlin V Kozack1, Stephen J Tereniak1
1Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States.
Journal of the American Chemical Society
|June 12, 2019
概括
这项研究揭示了在有氧酸乙氧化过程中形成的类物种,从而阐明了催化机制. 一个独特的配体使得氧气驱动的循环,促进了C-H氧化反应的催化剂的发展.
科学领域:
- 有机金属化学
- 催化剂
- 有机合成
背景情况:
- (II) 催化的C-H氧化,特别是酸乙氧化,被广泛研究.
- 关键的机械细节,包括循环限制步骤和催化剂静止状态,仍然不太清楚.
研究的目的:
- 通过使用Pd(OAc) 2和4,5--9-one (DAF) 催化剂系统,阐明氧化的有氧化氧化机制.
- 调查DAF连接体在支持分子氧作为氧化剂的催化周转中的作用.
主要方法:
- 操作光谱分析,包括X射线吸收和NMR光谱.
- 动力学研究以确定不同的反应阶段和催化剂中间体.
主要成果:
- 在反应过程中直接观察的物种形成和衰变.
- 确定两个动态阶段:形成Pd(I) 二次体的爆裂阶段和涉及π--Pd(II) 物种的爆裂后阶段.
- 在没有辅助催化剂的情况下,DAF连接体独特地支持有氧循环.
结论:
- 这项研究为催化氧化提供了前所未有的机理见解.
- 确定辅助配体在使 O2 驱动的催化循环中的作用.
- 为氧化反应开发改进的催化剂奠定了基础.
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