V. G. Nenajdenko

Synthesis of methylthiosubstituted heterocycles using the complex of trifluoromethanesulfonic anhydride with dimethyl sulfide

A new method was developed for the electrophilic introduction of methylthio group into a series of aromatic heterocyclic compounds through the hetaryl(dimethyl)sulfonium salts formed in the course of the reaction of the respective heterocycles with the complex of dimethyl sulfide and trifluoromethanesulfonic anhydride. By demethylation with triethylamine it was possible to obtain the methylthio-substituted heterocycles.

New method for the synthesis of α-chlorocinnamonitriles

A novel method for the preparation of nitriles of α-chlorocinnamic acid from aldehydes and ketones was proposed. Transformation of carbonyl compounds into hydrazones followed by treatment of the reaction mixture with CCl3CN in the presence of copper chloride(i) yields α-chlorocinnamonitriles.

Synthesis of annulated oligothiophenes

Reactions of 1,1-di(2-naphthyl)-2,2-dichloroethene and 1,1-di(2-benzothienyl)-2,2-dichloroethene with sulfur at 220–225 °C resulted in hitherto unknown oligothiophenes. Tetrathio[6]helicene was synthesized from 1,1-di(3-benzothienyl)-2,2-dichloroethene. Preparative pathway to helicene involving intramolecular ring closure of dithiol derived from 1,1-di-(3-benzothienyl)-2,2-dichloroethene was developed as an alternative to high temperature synthesis.

Reaction of α, β-unsaturated trifluoromethyl ketones with cyclic enamines

The reactions of α,β-unsaturated trifluoromethyl ketones containing aromatic and heteroaromatic substituents with 1-morpholinocyclopentene, 1-morpholinocyclohexene, and 1-methyl-4-morpholino-1,2,5,6-tetrahydropyridine were studied. The reactions proceeded stereospecifically to give the corresponding bicyclo[3.2.1]octane, bicyclo[3.3.1]nonane, and azabicyclo[3.3.1]nonane derivatives.

Synthesis of CF3-containing β-hetaryl-substituted enones

A procedure was developed for the synthesis of previously unknown CF3-containing β-azolyl-substituted enones by the reactions of 1,1,1-trifluoro-4-sulfonyl-3-butene-2,2-diols with various azoles. Quaternization of the azolyl group with methyl triflate afforded β-azolium-substituted enones in quantitative yields.

Reaction of 2-Aminothiazoles and Their Benzo- and Naphtho Derivatives with β-Sulfonyltrifluoromethylvinyldiols

By cyclocondensation of 2-aminothiazoles and their benzo and naphtho analogs with β-sulfonyltrifluoromethylvinyldiols, we have obtained a series of novel CF3-containing 6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidines. In the case of the sterically hindered 2-aminothiazoles, heterocyclization does not occur and the corresponding enamino ketones are formed.

Synthesis of β-trifluoroacetyl-substituted vinyl sulfones and vinyl sulfides

Oxidation of β-(trifluoroacetyl)vinyl sulfides afforded a series of the corresponding sulfones. The reactions of sulfones with various alkyl- and arylthiols were studied. These reactions provide the basis for a new procedure for the synthesis of β-(trifluoroacetyl)vinyl sulfides.

Synthesis of dithienopyrrole derivatives

Reactions of N-substituted succinimides with the Vilsmeier reagent leading to isomeric diformyldichloropyrroles were studied. The latter compounds were used for the synthesis of N-substituted dithieno[2,3-b:2′,3′-d]pyrrole and dithieno[2,3-b:3′,2′-d]pyrrole and their bromo derivatives as well. Dimers of N-alkyldithieno[2,3-b:2′,3′-d]pyrrole, novel promising materials for organic semiconductors, were synthesized.

Cyclocondensation of 2-Amino-1,3,4-thiadiazoles with β-Sulfonylvinyltrifluoromethyldiols

A series of CF3-containing 6,7-dihydro-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-ols was obtained by the interaction of 2-amino-1,3,4-thiadiazoles with β-sulfonylvinyltrifluoromethyldiols and their stereochemistry was established. The structure of 5-(phenylsulfonyl)-7-(trifluoromethyl)-6,7-dihydro-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-ol was confirmed by X-ray crystallography.

Synthesis of dienes with tetrafluorophenylene bridge based on the catalytic olefination reaction. New promising monomers for the design of molecular architectures with halogen—halogen interactions

Catalytic olefination of tetrafluoroterephthalic aldehyde hydrazone was studied. Dienes with a tetrafluorophenylene bridge containing different substituents at the double bonds were obtained. Stereochemistry of the reaction, as well as molecular structure and crystal packing of the dienes were studied.