Anodic oxidation of p-But-calix[4]arene-(OH)2-(OCH2CONEt2)2. Electrogeneration of a calixdiquinone in dichloromethane

The electrochemical oxidation of p-But-calix[4]arene-(OH)2-(OCH2CONEt2)2 1 has been investigated for the first time and was shown to result in the formation of the corresponding diquinone 3. The reaction proceeds via two successive two-electron irreversible oxidation steps both governed by an ECE mechanism. Alkali cations recognition can be realized by exhaustive oxidation of 1 in the presence of alkali salts.