我们开发了一种实用的 KO t Bu 或 KOH 催化的苄基 C(sp 3 )–H 键与各种醇的有氧交叉脱氢偶联,利用分子氧作为唯一氧化剂。这种无过渡金属和化学氧化剂的方法可以实现苄基C(sp 3 )–H键的直接和选择性烷氧基化,特别是容易发生过度氧化的初级苄基C–H键。此外,有氧氧化C-H/O-H交叉偶联方法为在温和反应条件下构建具有高化学选择性的苄基醚提供了一条实用且可持续的途径。
Environmentally Friendly and Highly Efficient Co(OAc)<sub>2</sub>-Catalyzed Aerobic Oxidation to Access 2,6-Di-Electron-Donating Group Substituted 4-Hydroxybenzaldehydes
作者:Jian-An Jiang、Jia-Lei Du、Zhong-Nan Zhang、Jiao-Jiao Zhai、Ya-Fei Ji
DOI:10.1080/00397911.2013.813052
日期:2014.5.19
developed for selectively preparing a series of valuable 2,6-dialkyl-, dialkoxyl-, and alkoxylalkyl-substituted 4-hydroxybenzaldehydes from corresponding 4-cresols in good to excellent yields, using a catalytic system of Co(OAc)2 · 4H2O (1.0 mol%)–NaOH (1.0 equiv)–O2 (1.0 atm) in aqueousethyleneglycol (EG/H2O = 20/1, v/v) at 50 °C. Furthermore, a plausible mechanism was proposed for the direct oxyfunctionalization