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.

Interaction between Ph(3)P and 1,3,2,4-benzodithiadiazine (1); its 6,7-difluoro (2), 5,6,8-trifluoro (3) and 5,6,7,8-tetrafluoro (4) derivatives; and 5,6,8-trifluoro-3,1,2,4-benzothiaselenadiazine (5) proceeded via a 1:1 condensation to give Ph(3)P═N-R iminophosphoranes (1a-5a, R = corresponding 1,2,3-benzodichalcogenazol-2-yls), which are inaccessible by general approaches based on the Staudinger and Kirsanov reactions. In contrast, neither Ph(3)As nor Ph(3)Sb reacted with 1 and 4. Molecular structures of 1a-5a and 5 were confirmed by X-ray diffraction (XRD). The crystals formed by chiral molecules of 2a-5a were racemic, whereas the crystal of 1a was formed by a single enantiomer. In all of the Ph(3)P═N-R derivatives, one of the Ph rings is oriented face-to-face to the hetero ring, R. Upon heating to ∼120 °C in squalane (1a, 3a, 4a) or dissolving in chloroform at ambient temperatures (1a, 2a, 4a), the Ph(3)P═N-R derivatives generated the 1,2,3-benzodithiazolyls (1b-4b, respectively) whose identity was confirmed by electron paramagnetic resonance (EPR). 2,1,3-Benzothiaselenazolyls 5b and 6b were detected by EPR as the main paramagnetic products of solution thermolysis of 5 and its 5,6,7,8-tetrafluoro congener (6), respectively. Passing a chloroform solution of 4a through silica column unexpectedly gave 5-6-6-6 tetracyclic (9) and 6-10-6 tricyclic (10) sulfur-nitrogen compounds, which were characterized by XRD.

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The complexes [Ln(DippForm)2(QAr)(THF)] [DippForm = N,N′‐(2,6‐diisopropylphenyl)formamidinate; Ln = Sm, Yb; QAr = SPh, SePh, TePh, SeC6F5, Se(p‐C6F4OMe)] were synthesized by reduction of corresponding dichalcogenides Ar2Q2 with the LnII formamidinates, [Ln(DippForm)2(THF)2]. All complexes with QPh ligands have similar molecular structure (determined by X‐ray diffraction), they are mononuclear due to the effective shielding of the central atom by the bulky amidinate ligands, and possess transoid disposition of the latter. The complexes with fluorinated phenyl groups (ArF) possess an additional coordination of an o‐F atom to the lanthanide ion. Only the compounds [Yb(DippForm)2(QArF)(THF)] easily lose the coordinated THF due to the sterically crowded coordination sphere, and the addition of THF is reversible even at ambient temperature. The Sm compounds are stable towards elimination of THF upon moderate heating. Similar crystal packing is found for most of the complexes, except for [Sm(DippForm)2(SPh)(THF)], [Yb(DippForm)2(SeC6F4OMe)(THF)] and [Yb(DippForm)2(SeC6F5)], which was rationalized as a consequence of interaction of FormDipp ligands from neighboring molecules to form intermolecular junctions. Analogous junctions were found in the majority of known complexes with Ln(DippForm)2 moiety (for all lanthanides). In the IR spectra the bands characteristic to the C–N, C–F and C–O bonds were revealed, some of which are noticeably influenced by the type of co‐ligands.

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The title compounds, including hybrids (n ¼ 6 n'), were assembled on benzene core in a unified way based on only one starting material C 6 F 5 NH 2 and a limited number of simple substitution and condensation reactions. The heterocyclic moieties were 1,3-diazoles, 1,2,3-triazoles, 1,2,5-thia(selena) diazoles, 1.4-diazines and 1,5-diazepines, as well as 1,3,2dioxaboroles. Representatives of all new scaffolds were charac-terized by XRD. Compounds synthesized are of biomedical interest in the context of apoptotic anticancer activity, and the 1,2,5-thiadiazole/1,3,2-dioxaborole hybrid also in that of neutron or/and proton capture therapy of cancer. New 1,2,5chalcogenadiazoles are protected forms of otherwise hardly accessible fluorine-containing di-and tetra-amines for further syntheses.