A facile and one-pot electrochemical method for the synthesis of a new anthraquinonethioether

The reaction of electrochemically generated anthradiquinone as a Michael acceptor with 2-mercaptobenzothiazole and 2- mercaptobenzoxazole,as nucleophiles in ethanol/water mixtures has been studied by means of cyclic voltammetry.Our voltammetric data indicate that produced anthradiquinone participates in Michael addition reaction with nucleophiles and via an ECEC mechanism converts to the new anthraquinonethioether derivatives.Based on an EC mechanism,the observed homogeneous rate constant of the Michael reaction of anthradiquinone with nucleophiles were estimated by comparing the experimental cyclic voltammograms with the digital simulated results.

Facile and one-pot,electro-organic synthesis of a new bis-quinone by the ECCE mechanism in green media

Electrochemical oxidation of 4-methyl catechol（1a） is investigated in the presence of 1,3-indandione（3）as nucleophile in phosphate buffer solution（0.2 mol/L,pH 6） mixed with ethanol as organic green solvent（50/50） using cyclic voltammetry and controlled-potential coulometry.The results indicated thatquinones derived from electro-oxidation of 1a,participated in a 1,4-Michael addition reaction with1,3-indandione（3） under ECCE mechanism.In this direction,a new bis-quinone was synthesized in high yield and good purity using a facile and convenient electrochemical pathway by carbon anode electrodes in an undivided cell.

A facile electrochemical method for the synthesis of new sulfonamide derivatives of potential biological significance

The electrochemical synthesis of some new sulfonamide derivatives was carried out via the electrochemical oxidation of 2,3-dihydrophthalazine-l,4-dione （1） in the presence of arylsulfinic acids （2a and 2b） as nucleophiles. The results show that, the electrogenerated phthalazine-l,4-dione （lox） participates in a Michael type addition reaction with 2a or 2b and via an EC mechanism to produce the corresponding sulfonamide derivatives. This method provides a one-pot procedure for the synthesis of new sulfonamide derivatives of potential biological significance in good yields without using toxic reagents at a carbon electrode in an environmentally friendly manner.

Electrosynthesis of hydroquinonethioethers using electrochemical oxidation of hydroquinone in the presence of thiouracil derivatives

Electrochemical oxidation of hydroquinone（1a） has been studied in the presence of 6-methyl-2-thiouracil（3a） and 6-propyl-2-thiouracil（3b） as nucleophiles in a DMF/buffer mixture,using cyclic voltammetry and controlled-potential coulometry.The results indicated that the p-quinone（2a） derived from 1a participates in a 1 4-Michael addition reaction with the thiouracil derivatives（3a–b） to form the corresponding hydroquinonethioether derivatives（6a–6b）.The electrosynthesis of these compounds（6a–b） has been successfully performed on carbon rod electrodes in an undivided cell in good yield and purity.

Oxidative Diels-Alder reaction of 2,5-dihydroxybenzoic acid with 1,3-cyclopentadiene

The electrochemical oxidation of 2,5-dihydroxybenzoic acid （1） has been studied in the presence of 1,3- cyclopentadiene （2） as a diene in water/ethanol （40/60, v/v） mixture using cyclic voltammetry and controlled-potential coulometry. A plausible mechanism for the oxidation of 1 in the presence of 2 is presented. Compound 1 was converted into bis-adduct 5 via electrooxidation, Diels-Alder reaction of 2 to anodically generated 3,6-dioxocyclohexa-l,4-dienecarboxylic acid （lox）, decarboxylation reaction, electrooxidation and Diels-Alder reaction. The electrochemical synthesis of 5 was performed in a one- pot reaction, without toxic reagents, at a carbon electrode in a simple cell using an environmentally friendlv method.

A promising green method in cyclization reaction.Oxidation of 3-methylcatechol in the presence of 1,10-phenanthroline

Electrochemical oxidation of 3-methylcatechol as a model compound has been studied in the presence of 1, 10-phenanthroline as a bi-dentate nucleophile in water/acetonitrile （70/30, v/v） solution using cyclic voltammetry and controlled-potential coulometry. The results revealed that anodically generated 3-methylcyclohexa-3,5-diene-1,2-dione participates in inter and intramolecular Michael addition reactions with 1,10-phenanthroline and via an ECEC pathway converts to the corresponding heterocyclic compound. The present work has ted to the development of a facile and one-pot method with high atom economy under ambient conditions and in an undivided cell using a carbon electrode.

Kinetic study of electrochemically induced Michael reaction of1,4-dihydroxyanthraquinone with acetylacetone and benzoylacetone

The electrochemical oxidation of 1,4-dihydroxyanthraquinone has been studied in the presence of acetylacetone and benzoylacetone as nucleophiles in a mixture of ethanol/water by means of cyclic voltammetry as a diagnostic technique.The results indicate the participation of electrochemically produced anthraquinone in the Michael addition reaction with acetylacetone and benzoylacetone to form the corresponding new anthraquinone derivatives.On the basis of the EC mechanism,the observed homogeneous rate constants（kobs）of the reaction of anthraquinone with acetylacetone and benzoylacetone were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results.