Palladium-Catalyzed Chemoselective Activation of sp<sup>3</sup> vs sp<sup>2</sup> C–H Bonds: Oxidative Coupling To Form Quaternary Centers
作者:Gang Hong、Pradip D. Nahide、Uday Kumar Neelam、Peter Amadeo、Arjun Vijeta、John M. Curto、Charles E. Hendrick、Kelsey F. VanGelder、Marisa C. Kozlowski
DOI:10.1021/acscatal.9b00091
日期:2019.4.5
activation of alkyl C–H bonds vs arene C–H bonds with Pd(OAc)2 has been found to be generalizable to a number of nucleophilic substrates, allowing the formation of a range of hindered quaternary centers. The substrates share a common mechanistic path wherein Pd(II) initiates an oxidative dimerization. The resultant dimer modifies the palladium catalyst to favor activation of alkyl C–H bonds, in contrast to
发现Pd(OAc)2对烷基C–H键与芳烃C–H键的氧化活化作用可推广至许多亲核底物,从而形成一系列受阻的季中心。底物共有一条共同的机理,其中Pd(II)引发了氧化二聚作用。与通常通过协同的金属化-去质子化机理观察到的趋势相反,生成的二聚体修饰钯催化剂以促进烷基C-H键的活化。值得注意的是,对于受阻底物,插入发生在烷基芳烃的末端。发现了两种不同的氧化剂系统来完成该过程。已经鉴定出参数,该参数预测哪些底物在该反应中有生产力。