A. L. Krasovsky

Diels–Alder reactions of β-trifluoroacetylvinylsulfones

Abstract Diels–Alder reactions of β-trifluoroacetylvinylsulfones with 1,3-dienes in CH 2 Cl 2 afforded corresponding mono- and polycycloadducts. A possibility of stereo- and regioselective cycloaddition was investigated. Elimination of sulfonyl group from cycloadducts leads to α,β-unsaturated trifluoromethylketones in good yields.

β-Trifluoroacetylvinyl phenyl sulfoxide—synthesis, Diels–Alder reaction and computational study

The Diels–Alder reaction of sulfoxide 2 with 1,3-dienes in CH2Cl2 afforded the corresponding CF3-containing mono- and polycycloadducts. In the case of the reaction of sulfoxide 2 and sulfonium salt 10 with cyclopentadiene, a mixture of four diastereomers was formed. The rotational potential energy surface (PES) of reagents 2, 10 was calculated and gave three minimum energy conformations with SO, Ph or the lone pair synperiplanar to the carbon–carbon double bond.

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.

A new method for the synthesis of CF3-containing aminovinyl ketones

A new method for the synthesis of aminovinyl trifluoromethyl ketones was developed. The method is based on the reactions of 4-sulfonyl-1,1,1-trifluorobut-3-ene-2,2-diols with various alkyl-, aryl-, dialkyl-, and alkylarylamines. The stereochemistry of the compounds obtained was studied.

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 new CF3-containing 3,4-dihydro-2H-pyrans

The reactions of vinyl sulfides with β-sulfonylvinyl trifluoromethyl ketones afforded CF3-containing 3,4-dihydro-2H-pyrans. An attempt to synthesize 1,1,1-trifluoro-3-(methylthio)but-3-en-2-one resulted in its dimerization into a CF3-containing 3,4-dihydro-2H-pyran.

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.

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.