S. K. Fedukovich

Electrocatalytic transformation of malononitrile and cycloalkylidenemalononitriles into spirotricyclic and spirotetracyclic compounds containing cyclopropane and pyrroline fragments

Electrolysis of cycloalkylidenemalononitriles and malononitrile in MeOH in an undivided cell in the presence of the NaBr—NaOMe mediator system gives spirotricyclic compounds containing cyclopropane and pyrroline fragments in 50—77% yields. Spirobicyclic and spirotricyclic tetracyanocyclopropanes undergo electrolysis in alcohols to afford spirotricyclic and spirotetracyclic products containing cyclopropane and pyrroline fragments in 50—93% yields.

Electrocatalytic transformation of malononitrile and cycloalkylidenemalononitriles into spirobicyclic and spirotricyclic compounds containing 1,1,2,2-tetracyanocyclopropane fragment

Electrolysis of malononitrile and cycloalkylidenemalononitriles in EtOH in an undivided cell in the presence of NaBr affords spirobicyclic compounds containing a 1,1,2,2-tetracyanocyclopropane fragment in 50—88% yields.

Stereoselective electrocatalytic cyclization of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acid esters to form 6-substituted (1R,5R,6R)*-4,4-dialkoxy-5-cyano-2-oxo-3-azabicyclo[3.1.0]hexane-1-carboxylic acid esters

Electrolysis of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acid esters in alcohols in an undivided cell in the presence of NaBr or NaOAc afforded 6-substituted (1R,5R, 6R)*-4,4-dialkoxy-5-cyano-2-oxo-3-azabicyclo[3.1.0]hexane-1-carboxylic acid esters in 80–95% yields.

Electrochemical oxidation of malonic esters in the presence of catalyst carriers — salts of hydriodic acid

Conclusions1.The throughgoing electrochemical oxidation of esters of malonic acid in the presence of catalyst carriers — salts of hydriodic acid — in methanol and ethanol leads to esters of ethylenetetracarboxylic acid and the products of the addition to it of alcohols and dialkyl malonates, namely 1-alkoxyethane-1,1,2,2-tetracarboxylic and propane-1,1,2,2,3,3-hexacarboxylic esters.2.The results of the reaction depends to a significant degree on the temperature and the nature of the cation in the catalyst carrier. Under optimal conditions, each of the enumerated esters can be obtained with the yield of 50–80%.

ELECTROCHEMICAL CO-OXIDATION OF C-H ACIDS AND METHANOL AS A NEW ROUTE TO FUNCTIONALIZED CYCLOPROPANES

Electrolysis of dimethyl malonate or methyl cyanoacetate in methanol in the presence of LiCl in an undivided cell leads to formation of 1,1,2,2-cyclopropanetetracarboxylic derivatives.

Electrochemical selective trimerization of malonic esters into esters of propane-1,1,2,2,3,3-hexacarboxylic acid in the presence of hydrobromic acid salts

ConclusionsThe electrochemical oxidation of malonic esters in methanol, ethanol, or acetonitrile in the presence of alkali metal bromides as catalyst-carriers, with the use of 1.8–2 F of electricity per mole of the starting malonic ester leads to esters of propane-1,1,2,2,3,3-hexacarboxylic acid in a yield of up to 90%.

Electrochemical cyclization of the tetramethyl ester of propane-1,1,3,3-tetracarboxylic acid in the presence of salts of hydrogen halides

Conclusions1.On electrolysis in methanol in the presence of the catalyst carrier NaI, tetramethyl propane-1,1,3,3-tetracarboxylate cyclizes with the exclusive formation of tetramethyl cyclopropane-1,1,2,2-tetracarboxylate with the yield up to 98%.2.In the presence of NaBr and LiCl, hexamethyl pentane-1,1,3,3,5,5-hexacarboxylate, hexamethyl cyclopentane-1,1,2,2,4,4-hexacarboxylate, and tetramethyl tetrahydrofuran-2,2,4,4-tetracarboxylate are also formed; the last may be obtained with the yield up to 60%.

Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides as mediators

Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides follows two different pathways depending on the nature of the cation. In the presence of Lil, alkyl 1,1,2,2,3,3-propanetetracarboxylates were obtained in 85–98% yields. In the presence of Nal, Kl, or Bu4NI, the formation of 1,1,2,2-ethanetetracarboxylates and their subsequent dehydrogenation to ethenetetracarboxylates was the main reaction pathway.

Electrochemical oxidation of tetramethyl esters of α,α,ω,ω-alcaneteracarboxylic acids

Cyclization of esters of butane-1,1,4,4- and pentane-1,1,5,5-tetracarboxylic acids during electrolysis in methanol in the presence of Nal produces, with a yield of 95%, the esters of cyclobutane-1,1,2,2- and cyclopentane-1,1,2,2-tetracarboxylic acids. Under similar conditions, esters of the highest α,α,ω,ω-alkanetetracarboxylic acids undergo iodation and hydroxymethylation due to electrical oxidation of methanol to formaldehyde. During electrolysis in methanol in the presence of NaOAc, the esters of α,α,ω,ω-alkanetetracarboxylic acids undergo effective hydroxymethylation, followed by cyclization into substituted five- and six-member lactones, or tetrahydrofurans when structurally possible.

Electrochemical oxidation of esters of ethane-1,1,2,2-tetracarboxylic acid in the presence of electron carrier catalysts

Conclusions1.Electrochemical oxidation of esters of ethane-1,1,2,2-tetracarboxylic acid in the presence of hydrohalic acid salts in acetonitrile leads to esters of ethylenetetracarboxylic acid; in alcohols not only an oxidative dehydrogenation takes place, but also esters of 1-alkoxyethane-1,1,2,2-tetracarboxylic acid are formed.2.When the reaction is carried out in methanol, the yield of the ester of ethylenetetracarboxylic acid and the ester of 1-methoxyethane-1,1,2,2-tetracarboxylic acid depends on the temperature, type of carrier-catalyst, and under the optimal conditions, each of the esters can be obtained in a yield of up to 80%.3.A mechanism has been proposed for the electrochemical oxidation of esters of ethane-1,1,2,2-tetracarboxylic acid, including the formation of the α-anion of the ester on a cathode, generation of a molecular halogen on the anode and their chemical transformations in solutions.