Arylation of hydrocarbons enabled by organosilicon reagents and weakly coordinating anions
Arylation of hydrocarbons enabled by organosilicon reagents and weakly coordinating anions
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DOI：
10.1126/science.aam7975
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发表时间：
2017-03-31
期刊：
影响因子：
56.9
通讯作者：
Nelson, Hosea M.
中科院分区：
文献类型：
--
作者：
Shao, Brian;Bagdasarian, Alex L.;Nelson, Hosea M.
在过去的 80 年里，苯基阳离子中间体参与了各种 C-H 芳基化反应。尽管这些例子激发了一些理论和机理研究，但芳基阳离子当量在有机方法学中受到的关注有限。它们的高能、混杂的反应特性阻碍了其在选择性分子间过程中的应用。我们报告了克服这些挑战的反应设计。具体来说，我们发现通过硅介导的氟化物活化产生的β-硅稳定的芳基阳离子等价物会插入sp(3)和sp(2) C-H键。该反应流形为烃类的催化芳基化提供了框架，包括简单的烷烃，例如甲烷。该过程使用地球丰富的引发剂（1 至 5 摩尔%），并在温和条件（30 至 100 摄氏度）下进行。
Over the past 80 years, phenyl cation intermediates have been implicated in a variety of C-H arylation reactions. Although these examples have inspired several theoretical and mechanistic studies, aryl cation equivalents have received limited attention in organic methodology. Their high-energy, promiscuous reactivity profiles have hampered applications in selective intermolecular processes. We report a reaction design that overcomes these challenges. Specifically, we found that beta-silicon-stabilized aryl cation equivalents, generated via silylium-mediated fluoride activation, undergo insertion into sp(3) and sp(2) C-H bonds. This reaction manifold provides a framework for the catalytic arylation of hydrocarbons, including simple alkanes such as methane. This process uses low loadings of Earth-abundant initiators (1 to 5 mole percent) and occurs under mild conditions (30 degrees to 100 degrees C).