Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.
J Org Chem. 2021 Apr 16;86(8):5771-5777. doi: 10.1021/acs.joc.1c00231. Epub 2021 Mar 31.
Arene substitution patterns are well-known to affect the regioselectivity of a given transformation but not necessarily the type of reactivity. Herein, we report that the substitution pattern of alkoxyarenes dictates whether a putative one-electron or two-electron reaction predominates in reactions with Selectfluor. A series of amination products is presented, resulting from the single-electron oxidation of electron-rich arenes followed by direct C-H to C-N bond formation. We demonstrate the ability of this transformation to synthesize medicinally and biologically relevant nitrogen heterocycles. Lastly, this unusual "mechanistic switch" is probed with computational chemistry and competition experiments.
芳环取代模式众所周知会影响特定转化的区域选择性，但不一定会影响反应类型。在此，我们报告称烷氧基芳环的取代模式决定了在与 Selectfluor 的反应中主要是单电子反应还是双电子反应。一系列的胺化产物被提出，这是通过富电子芳环的单电子氧化，然后直接 C-H 到 C-N 键形成而产生的。我们展示了这种转化在合成具有医学和生物学相关性的氮杂环中的能力。最后，通过计算化学和竞争实验对这种不寻常的“机制转换”进行了探究。
