Copper salt-crown ether systems as catalysts for the oxidation of isopropyl arenes with tertiary hydroperoxides to peroxides

Symmetrical and unsymmetrical peroxides can be obtained by the oxidation of isopropyl arenes with tertiary hydroperoxides in the presence of copper sa lt-crown ether as catalysts. The efficiency of the investigated catalytic s ystem enhances markedly in the presence of some alkali metal salts, with a cation diameter corresponding to the inner diameter of the crown ether. The oxidation of isopropyl arenes with hydroperoxides in the presence of a cop per salt-crown ether-alkali metal salt catalytic system proved to be a simp le and efficient method for the synthesis of ditertiary peroxides. A possib le mechanism of this phenomenon is discussed. The results obtained confirm strongly that phase transfer catalysis operates in the investigated reactio n. (C) 2001 Elsevier Science B.V. All rights reserved.