V. M. Rogovik

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.

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.

Formation of fluorosulfatodimerization products in reactions of perfluoroaliphatic α,β-unsaturated carbonyl compounds and conjugated dienes with electrochemically generated peroxydisulfuryldifluoride

Reactions of fluoroaliphatic α,β-unsaturated carbonyl compounds and perfluoro-2,7-dimethylocta-3,5-diene with electrochemically generated peroxydisulfuryldifluoride proceed to give both 1∶1 adducts and fluorosulfatodimerization products, whose formation is explained by generation of heteroallyl and allyl radicals due to the addition of a fluorosulfonyloxy radical to the sterically hindered vinyl carbon atom.

EPR study of the transformations of fluoroalkenyl radicals

ConclusionsFluorinated alkenyl radicals containing a double bond at position 4 or 5 relative to the radical site are converted into relatively stable radicals, apparently due to their cyclization.

Fluoroaliphatic esters of fluorosulfonic acid. 6. Interaction of fluorine-containing α,β-bis-fluorosulfatocarbonyl compounds with nucleophilic reagents

Fluorine-containing α,β-fluorosulfatocarbonyl compounds interact with halides of alkali metals with the formation of α-halogeno-β-dicarbonyl derivatives.

SYNTHESIS AND REACTIVITY OF POLYFLUORINATED FLUOROSULFATOCARBINOLS IN THE PRESENCE OF BASES

Compounds CF3CR(OH)CF2OSO2F (I) (R=MeO, Ph) were synthesized by the reaction of α-(fluorosulfato)pentafluoroacetone with MeOH or C6H6/A1Cl3. In the presence of bases compound (I), depending on the reaction conditions, forms either cyclic sulfates or products of their isomerization — substituted α-fluorosulfato-trifluoropropionic acid fluorides which are capable of nucleophilic substitution of FSO3 groups in reaction with the nucleophiles.

Fluoroaliphatic esters of fluorosulfonic acid. 3. Decomposition of poly(fluorosulfato)perfluoroalkanes under the action of antimony pentafluoride

Vicinal bis(fluorosulfato)perfluoroalkanes containing FSO3 groups in the middle of a fluorocarbon chain eliminate one or two molecules of sulfuryl fluoride under the action of SbF5, forming a mixture of isomeric α-fluorosulfato ketones and α-diketones.

Fluoroaliphatic esters of fluorosulfonic acid. 4. Reactions of α-fluorosulfatoperfluoro ketones with nucleophilic reagents

Abstractα-Fluorosulfatoperfluoroethyl isopropyl ketone I and fluorosulfatopentafluoroacetone II react with alkali metal chlorides and bromides to form the corresponding α-haloperfluoro ketones as a result of direct nucleophilic substitution.