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稳定-Pd (IV) 复合物的合成和反应性相关于单N (N) 导向的C (sp) -H功能化过程

William G Whitehurst¹, Matthew J Gaunt¹

¹Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom.

Journal of the American Chemical Society

|July 23, 2020

概括

研究人员合成了稳定的- (IV) 复合物,对于C (sp3) -H功能化至关重要. 这些新型环复合物与核友反应,促进了催化研究.

科学领域:

有机金属化学
催化剂
合成化学

背景情况:

基-Pd (IV) 复合物是Pd催化C (sp3) -H功能化的拟议机制中的关键中间体.
由于高价值Pd(IV) 中心的不稳定性,将Pd(IV) 复合物与环基质分离起来是具有挑战性的.

研究的目的:

合成和表征稳定,可分离的OCO支基-Pd (IV) 复合物.
探索这些新型复合体与各种核友的反应性.
阐明从Pd(IV) 复合体中核介导的还原性消除的机制.

主要方法:

用OCO支的基-Pd (IV) 复合物的合成,其中包括环基和氧基.
氨基-Pd (IV) 复合物的与O-和N-核友的反应.
使用氧化物衍生Pd(IV) 复合物的机理研究,以研究降解性消除.

主要成果:

首个稳定和可分离的基-Pd (IV) 复合物的成功合成来自循环化单一基.
氨基-Pd (IV) 复合物在与O-和N-核友反应时有效地产生了γ-功能化的胺产物.
机理学研究显示,在核介导的减少消除过程中,一种新的阴离子Pd(IV) 物种的介导作用.

结论:

由OCO支持的稳定-Pd (IV) 复合物可以从循环化N-捐赠基质中合成.
这些复合物通过核友攻击作为g-功能化胺合成的有价值的前体.
这项研究发现了一种新的阳离子Pd(IV) 中间体,进步了对催化中的减排机制的理解.

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