Electrochemical dimerization of 4-methylesculetin: Synthesis and kinetic study of a highly-oxygenated dimer

This paper describes the electrochemical dimerization of 4-methylesculetin via anodic oxidation. The voltammetric data show that electrochemically generated ortho-benzoquinone participates in Michael addition reaction with starting molecular (4-methylesculetin) forms the corresponding highly-oxygenated dimer. The mechanism of dimerization has been studied in water/acetonitrile mixture using cyclic voltammetry and controlled-potential coulometry. The electrochemical synthesis of this highly-oxygenated dimer has been successfully performed in an undivided cell in good yield and purity. Furthermore, the observed homogeneous rate constants of the chemical reaction between ortho-benzoquinone and 4-methylesculetin were estimated by comparing the experimental cyclic voltammetric curves with the digitally simulated ones. (C) 2010 Elsevier B.V. All rights reserved.