Counterion Control of
<i>t</i>
‐BuO‐Mediated Single Electron Transfer to Nitrostilbenes to Construct
<i>N</i>
‐Hydroxyindoles or Oxindoles
作者:Yingwei Zhao、Haoran Zhu、Siyoung Sung、Donald J. Wink、Joseph M. Zadrozny、Tom G. Driver
DOI:10.1002/anie.202104319
日期:2021.8.23
tert-Butoxide unlocks new reactivity patterns embedded in nitroarenes. Exposure of nitrostilbenes to sodium tert-butoxide was found to produce N-hydroxyindoles at room temperature without an additive. Changing the counterion to potassium changed the reaction outcome to yield solely oxindoles through an unprecedented dioxygen-transfer reaction followed by a 1,2-phenyl migration. Mechanistic experiments
叔丁醇解锁了硝基芳烃中嵌入的新反应模式。研究发现,在室温下,硝基芪与叔丁醇钠接触即可产生 N-羟基吲哚,无需任何添加剂。将抗衡离子改为钾改变了反应结果,通过前所未有的双氧转移反应和随后的 1,2-苯基迁移仅产生羟吲哚。机理实验证实这些反应通过自由基中间体进行,并表明抗衡离子配位控制是否形成羟吲哚或 N-羟基吲哚产物。