Oxidation products of paramethyl-substituted hindered phenols
申请人:The Dow Chemical Company
公开号:US04915875A1
公开(公告)日:1990-04-10
Paramethyl-substituted hindered phenols are selectively oxidized by contacting with an oxidizing agent at elevated temperatures in the presence of a heterogeneous oxidative coupling catalyst. In the absence of an optional nucleophile the products comprise carbon-carbon oxidative coupling products. In the presence of a nucleophile, addition products result that may be further oxidized by continued exposure to the oxidizing agent to yield substituted p-hydroxybenzaldehydes.
Selective copper(ii)-mediated oxidative coupling of a nucleophilic reagent to the para-methyl group of 2,4,6-trimethylphenol
作者:Christophe Boldron、Şeniz Özalp-Yaman、Patrick Gamez、Duncan M. Tooke、Anthony L. Spek、Jan Reedijk
DOI:10.1039/b507199b
日期:——
A copper(II) neocuproine system has been developed for the efficient and very selective 1,6-addition of a nucleophile to the para-methyl group of 2,4,6-trimethylphenol. Crystallographic and spectroscopic data point towards the involvement of a μ-methoxo–μ-phenoxo-bridged copper species which appears to generate a highly reactive quinone methide intermediate that can be attacked by a nucleophilic reagent.
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