Green Organic Solvent-Free Oxidation of Alkylarenes with tert-Butyl Hydroperoxide Catalyzed by Water-Soluble Copper Complex

Abstract

<jats:title>Abstract</jats:title><jats:p>Different benzylic compounds were efficiently oxidized to the corresponding ketones with aqueous 70% <jats:italic>tert-</jats:italic>butyl hydroperoxide (TBHP) and the catalytic system composed of CuCl<jats:sub>2</jats:sub>.2H<jats:sub>2</jats:sub>O and 2,2’-biquinoline-4,4’-dicarboxylic acid dipotassium salt (BQC). The catalytic system CuCl<jats:sub>2</jats:sub>/BQC/TBHP allows obtaining high yields at room temperature under organic solvent-free conditions. The interest of this system lies in its cost effectiveness and its benign nature towards the environment. Benzylic <jats:italic>tert</jats:italic>butylperoxy ethers and benzylic alcohols were observed and suggested as the reaction intermediates. Analysis of organic products by atomic absorption did not show any contamination with copper metal. In terms of efficiency, CuCl<jats:sub>2</jats:sub>/BQC system is comparable or superior to the most of the catalytic systems described in the literature and which are based on toxic organic solvent.</jats:p>