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Currently, the chemistry of organofluorine compounds is a leading and rapidly developing area of organic chemistry. Fluorine present in a molecule largely determines its specific chemical and biological properties. This thematic issue covers the trends of organofluorine chemistry that have been actively developed in Russia the last 15 – 20 years. The review describes nucleophilic substitution and heterocyclization reactions involving fluorinated arenes and quinones and skeletal cationoid rearrangements in the polyfluoroarene series. The transformations involving CF3-substituted carbocations and radical cations are considered. Heterocyclization and oxidative addition reactions of trifluoroacetamide derivatives and transformations of the organic moiety in polyfluorinated organoboranes and borates with retention of the carbon – boron bond are discussed. Particular attention is devoted to catalytic olefination using freons as an efficient synthetic route to fluorinated compounds. The application of unsymmetrical fluorine-containing N-heterocyclic carbene ligands as catalysts for olefin metathesis is demonstrated. A variety of classes of organofluorine compounds are considered, in particular, polyfluorinated arenes and 1,2-diaminobenzenes, 1-halo-2-trifluoroacetylacetylenes, α-fluoronitro compounds, fluorinated heterocycles, 2-hydrazinylidene-1,3-dicarbonyl derivatives, imines and silanes. The potential practical applications of organofluorine compounds in fundamental organic chemistry, materials science and biomedicine are outlined. The bibliography includes 1019 references.

1,2,3-Triketone 2-(antipyrin-4-yl)hydrazones were synthesized via the azo-coupling reactions of 1,3-diketones with 2-(antipyrin-4-yl)diazonium chloride. The fluoroalkyl-containing hetarylhydrazone enters into cyclocondensation with hydrazines at the 1,3-dicarbonyl fragment to yield 3-tetrafluoroethyl derivatives of pyrazole. It was found that 1,2,3-triketone 2-(antipyrin-4-yl)hydrazones and N-(2-hydroxyethyl)-substituted pyrazole exhibit analgesic activity comparable with that of their structural analog analgin (metamizole sodium), but do not possess antipyretic properties. In contrast, N-phenyl-substituted pyrazole did not exhibit analgesic properties but produced a certain antipyretic effect four hours after pyrogenic administration. Fluoroalkyl-containing compounds are less toxic substances than nonfluorinated 2-(antipyrin-4-yl)hydrazone and analgin.As is known, the widely used analgesic and antipyretic drugs are rather toxic substances [1]. We attempted to modify the antipyrine structure so as to obtain new low-toxicity compounds possessing analgesic and antipyretic properties.Using the azo-coupling reactions of 1,3-diketones (Ia and Ib) with 2-(antipyrin-4-yl)diazonium chloride (II) in the presence of sodium acetate, we obtained the corresponding 1,2,3-triketone 2-(antipyrin-4-yl)hydrazones (IIIa and IIIb). The proposed structures of these products were confirmed by the data of elemental analyses and the results of IR and 1 H NMR spectroscopic measurements. Indeed, the presence of characteristic absorption bands due to carbonyl groups (at 1660 -1680 cm -1 ) and a weak band due to the stretching vibrations of amino groups of the hydrazone fragment (at 3300 -3470 cm -1 ) in the IR spectra, as well as the absence of signals from methane protons in the 1 H NMR spectra, showed evidence for a hydrazone-diketone tautomer structure of the synthesized compounds.

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