S. R. Sterlin

ELECTROCHEMICAL REDUCTION OF CO2 IN THE PRESENCE OF 1,3-BUTADIENE USING A HYDROGEN ANODE IN A NONAQUEOUS MEDIUM

The possibility of anodic generation of a solvated proton on a gas-diffusion electrode in an aprotic medium in the presence of carbon dioxide and 1,3-butadiene has been demonstrated. Formic acid was shown to be the only product of the reaction in the initially aprotic medium with the use of a hydrogen gas-diffusion anode. The influence of the counterion on the reactivity of the CO2.− radical anion in electrocarboxylation was shown experimentally.

Electrocarboxylation of 1,4-dibromobut-2-ene in a CO2-DMF liquid mixture

The possibility of synthesizing dihydromuconic acid by cathodic carboxylation of 1,4-dibromobut-2-ene in the liquid CO2-aprotic solvent system was investigated. The low yield of dihydromuconic acid in this reaction was explained by the competing reductive debromodimerization and oligomerization of 1,4-dibromobut-2-ene, which lead to the predominant formation of 1,8-dibromo-2,6-octadiene and polymeric products.

Electrophilic isomerization of fluoroaliphatic oxygen-containing compounds

An unusual electrophilic cyclization of fluorine-containing carbonyl compounds and α-oxides was discovered. Upon the action of SbF5, perfluorinated ketones, diketones, and α-oxides isomerize to oxolanes. This reaction proceeds with the obligatory participation of the terminal CF3 group.

Electrochemical trifluoromethylation of aromatic compounds

It was shown that the current yield of the products of anodic trifluoromethylation of arenes correlates with the adsorptivity and the rate of electrooxidation of arenes on the surface of a platinum electrode.

Substitutive sulfotrioxidation of branched perfluoroolefins

We have studied the insertion of SO3 into the C-F bond of perfluoroolefins under conditions of electrophilic catalysis. It was shown that sufficiently high allylic mobility of the fluorine atoms is only preserved when in the allylic triad, in addition to the substituted fluorine; also not less than three fluorine atoms are present in the α and γ positions.

ESR study of the free radicals formed in the photolysis of α-ketofluorosulfates

ESR spectroscopy was used to establish that the UV irradiation of α-ketofluorosulfates containing an OSO2F group at a tertiary carbon atom gives radicals formed upon cleavage of the C-OSO2F bond. If the OSO2F group is attached to a primary or secondary carbon atom, we observe ordinary photodecomposition with cleavage of the acyl—carbon bond. The ESR spectra of the new radicals were studied. Replacement of fluorine by the OSO2F group in the trifluoromethyl radical leads to compression of the radical site. Branched α-oxoperfluoroalkyl radicals are not heteroallylic and the unpaired electron is localized largely on the carbon atom. The [(CF3)2CF]2ĊC(O)CF3 radical is stable in the air.

Fluoroaliphatic esters of fluorosulfonic acid. 5. Conjugate radical fluorosulfatohalogenation of higher fluoroolefins

A study has been made of the electrochemical fluorosulfation of perfluoro-2-alkenes in the presence of halogens, leading to the formation of fluoroaliphatic vicinal fluorosulfatohalides. The reaction proceeds as a conjugate radical addition of peroxydisulfuryl difluoride and the halogen at the double bond of the olefin; the ratio of the resulting regioisomers is determined by steric factors.

Electrophilic acylation of fluoroolefins by perfluorinated ?,?-unsaturated carboxylic acid fluorides

Abstractα,β-Unsaturated perfluorocarboxylic acid fluorides react with fluoroolefins in the presence of SbF5 under mild conditions to give vinyl ketones.

Fluoroaliphatic esters of fluorosulfonic acid. 2. Reaction of bis(fluorosulfato)perfluoroalkanes with cesium fluoride

Abstract2,3-Bis(fluorosulfato)perfluoroalkanes split under the action of CsF in the absence of solvents, giving a mixture of α-fluorosulfatoperfluoro ketones, perfluoroalkene sulfates, and perfluoro α-diketones. The occurrence of these reactions in solutions results mainly in the formation of oxides of the corresponding fluoroolefins or products of their conversions. The reactions carried out are the first examples of nucleophilic substitution at a secondary carbon atom in a perfluorinated saturated chain.

ELECTROCHEMICAL PERFLUOROALKOXYLATION OF AROMATIC COMPOUNDS

New approaches to the electrochemical synthesis of aryl perfluoroalkyl ethers based on a) the electrooxidation of perfluorocarboxylic acid on a consumable PbO2 anode and b) the simultaneous anodic oxidation of the “aromatic compound-alkaline perfluoroalkoholate” system on a platinum electrode were proposed.