Kinetic Study of Electrochemically Induced Michael Reactions of o-Quinones with Meldrum’s Acid Derivatives. Synthesis of Highly Oxygenated Catechols D. Nematollahi* and H. Shayani-jam Faculty of Chemistry, UniVersity of Bu-Ali-Sina, Hamadan, 65174, Iran nemat@basu.ac.ir ReceiVed January 17, 2008 Electrochemical oxidation of catechols has been studied in the presence of Meldrum’s acid derivatives as nucleophiles in aqueous solution, by means of cyclic voltammetry and controlled-potential coulometry. Catechols in the Michael addition reaction react with Meldrum’s acids to form adducts that can undergo electrooxidation. Such products were obtained in good yields as confirmed by controlled potential electrosynthesis. Such products can be generated in aqueous solutions by means of electrosynthesis, using a carbon electrode in an undivided cell. Furthermore, the homogeneous rate constants of the chemical reaction interposed between electron transfers were estimated by comparing the experimental cyclic voltammetric curves with the digitally simulated ones. Introduction Investigation of catechol derivatives may lead to the discovery of selectively acting, biodegradable agrochemicals with a human, animal, and plant compatibility. 1,2 One of the most important groups of catechols are catecholamines. Catecholamines are compounds containing a catechol nucleus and amine group on a chain of two carbon atoms meta or para to the phenolic hydroxyl groups and are bioenergetic amines that play quite an important role as neurotransmitters in the central nervous system (CNS). And accordingly, their electrochemistry has been investigated extensively. 3 Furthermore, o-quinones are of con- siderable interest because many drugs such as doxorubicin, daunorubicin, and mitomycin C in cancer chemotherapy contain quinones, 4 whereas various other quinones have found use in industry. 5 Some of them also exhibit antitumor and antimalarial activities 6 and many of them are also involved in enzyme inhibition and DNA cross-linking. 7 Also, it is demonstrated in comparison with simple catechols and quinones that highly oxygenated catechols 8,9 and quinones 10 exhibit interesting biological activities. After the valuable published paper on the electrochemical oxidation of substituted catechols by Ryan et al. in 1980, 11 in recent years we and others have investigated the electrochemical oxidation of some catechols in the presence * Corresponding author. Fax: 0098-811-8272404, Phone: 0098-811-8271541. (1) AMICBASE-EssOil, Database on Natural Antimicrobials; Review Sci- ence: Germany (1999-2002). (2) Pauli, A. Antimicrobial Properties of Catechol DeriVatiVes; Proceeding of the 3rd World Congress on Allelopathy: Tsukuba, Japan, August, 2002. 10.1021/jo800115n CCC: $40.75  2008 American Chemical Society 3428 J. Org. Chem. 2008, 73, 3428–3434 Published on Web 04/09/2008