Michail N. Elinson

Electrocatalytic multicomponent assembling of isatins, 3-methyl-2-pyrazolin-5-ones and malononitrile: facile and convenient way to functionalized spirocyclic [indole-3,4'-pyrano[2,3-c]pyrazole] system.

Electrochemically induced catalytic multicomponent transformation of isatins, 3-methyl-2-pyrazolin-5-ones and malononitrile in ethanol in an undivided cell in the presence of sodium bromide as an electrolyte results in the formation of spirooxindoles with fused functionalized pyrano[2,3-c]pyrazole system in 78–99} yields. The developed efficient electrocatalytic approach to medicinally relevant spirocyclic [indole-3,4′-pyrano[2,3-c]pyrazoles] is beneficial from the viewpoint of diversity-oriented large-scale processes and represents a novel example of facile environmentally benign synthetic concept for electrocatalytic multicomponent reaction strategy.

Stereoselective electrochemical transformation of alkylidenecyanoacetates and malonate into (E)-3-substituted-2-cyanocyclopropane-1,1,2-tricarboxylates

Abstract Electrolysis of malonate and alkylidenecyanoacetates in alcohols in the presence of sodium bromide in an undivided cell results in the stereoselective formation of (E)-3-substituted 2-cyanocyclopropane-1,1,2-tricarboxylates in 75–85% yields.

Electrochemical transformation of malononitrile and ketones into 3,3-disubstituted-1,1,2,2-tetracyanocyclopropanes

Abstract Electrolysis of malononitrile in the presence of ketones and NaBr in ethanol in undivided cell results in formation of 3,3-disubstituted-1,1,2,2-tetracyanocyclopropanes.

Electrochemically induced multicomponent assembling of isatins, 4-hydroxyquinolin-2(1H)-one and malononitrile: a convenient and efficient way to functionalized spirocyclic [indole-3,4′-pyrano[3,2-c]quinoline] scaffold

Electrochemically induced catalytic multicomponent transformation of isatins, 4-hydroxyquinolin-2(1H)-one and malononitrile in ethanol in an undivided cell in the presence of sodium bromide as an electrolyte results in the formation of spirooxindoles with fused functionalized indole-3,4′-pyrano[3,2-c]quinoline] scaffold in 75–91% substance yields and 500-600% current yield. The developed efficient electrocatalytic approach to medicinally relevant [indole-3,4′-pyrano[3,2-c]quinoline] scaffold is beneficial from the viewpoint of diversity-oriented large-scale processes and represents a novel example of facile environmentally benign synthetic concept for electrocatalytic multicomponent reactions.

Electrochemical transformation of cyanoacetic ester and aldehydes into 3-substituted 1,2-dicyanocyclopropane-1,2-dicarboxylates

Abstract Electrolysis of cyanoacetic ester in the presence of aldehydes and NaBr in alcohols in an undivided cell results in formation of 3-substituted 1,2-dicyanocyclopropane-1,2-dicarboxylates.

Electrocatalysis in MIRC reaction strategy: facile stereoselective approach to medicinally relevant spirocyclopropylbarbiturates from barbituric acids and activated olefins

The combined electrolysis of barbituric acids and benzylidenemalononitriles or benzylidenecyanoacetates in methanol in an undivided cell in the presence of sodium bromide results in efficient MIRC (Michael-initiated ring-closure) formation of the corresponding spirocyclopropylbarbiturates in 45–93% yield. The electrocatalytic reaction proceeds smoothly under neutral and mild conditions with benzylidenemalononitriles or benzylidenecyanoacetates bearing both electron-donating and electron-withdrawing groups. NMR and single X-ray diffraction studies indicate that the electrocatalytic MIRC transformation of barbituric acids and benzylidenecyanoacetates results in the stereoselective formation of spirocyclopropanes with an (E)-configuration of aryl and alkoxycarboxylate substituents. The implication of electrocatalysis in the MIRC reaction strategy allows the combination of the synthetic virtues of both methods and accounts for an efficient approach to medicinally relevant spirocyclopropylbarbiturates avoiding inconvenient direct use of molecular halogen or halogenated substrates in accordance with the concepts of modern green chemistry.

Electrocchemicai oxidatiob of ketones in methanol in the presence of alkali metal bromides

Abstract Electrochemical oxidation of methyl ketones in methanoi in the presence of alkali metal bromides affords methyl carboxylates. Benzyl alkyl ketones are transformed under similar conditions into methyl 3-phenylalkanoates, while ketones lacking σ-benzyl or σ-methyl group are oxidized into σ-hydroxyketals.

ELECTROCHEMICAL CYCLODIMERIZATION OF ALKYLIDENEMALONATES

Abstract Electrolysis of dimethyl alkylidenemalonates RCH = C(COOMe)2 (R = n−Alk, Ph) in an undivided cell in MeOH in the presence of alkali metal halide as mediator, leads to the formation of cyclic dimers, i.e., 3,4-disubstituted 1,1,2,2-cyclobutanetetracarboxylates. The reaction proceeds via the reductive coupling of two substrate molecules at cathode and the cyclization of a hydrodimer dianion by its interaction with an active form of a mediator, an anode-generated halogen.

Electrochemical synthesis of cyclopropanes

Data on methods of electrochemical synthesis of cyclopropanes are summarized and described systematically. Direct electrochemical methods to afford cyclopropanes in both cathodic and anodic processes are considered. Among indirect electrochemical methods such as the processes employing electrogenerated bases and also those involving electrogenerated metal complexes, attention is focused on the most promising methods for the synthesis of functionally substituted cyclopropanes, namely, the electrocatalytic cascade and multicomponent transformations of CH acids and also the joint electrolysis of CH acids and activated alkenes or carbonyl compounds in the presence of alkali metal halides as mediators. The bibliography includes 62 references.

Indirect electrochemical oxidation of cyclic ketones: Influence of ring size, mediator and supporting electrolyte on the result of the reaction

Abstract The result of the indirect electrochemical oxidation of cyclic ketones in methanol in an undivided cell in the presence of sodium halides depends on the ring size of ketone and the type of mediator. Selectivity of the reaction in some cases and current efficiency are increased by addition of supporting electrolyte - sodium hydroxide. Formation of cyclic 2,2-dimethoxycycloalkanols and the electrochemically induced Favorskii rearrangement with the formation of methyl cycloalkencarboxylates containing in the ring one carbon atom less than starting ketone are the main ways of the indirect electrochemical oxidation of cyclic ketones.