Alexey O. Miller

Cyclic aryleneazachalcogenenes. Part III [1] synthesis of polyfluorinated 2,1,3-benzothia-(selena) diazoles

Abstract 1-(4-X-Tetrafluorophenyl)-3-trimethylsilyl-1,3-diaza-2- thiaallenes (X = H, CH 3 , Br, F, CF 3 ) treated with CsF in acetonitrile or THF cyclized to 6-X-4,5,7-trifluoro-2,1,3-benzothiadiazoles whose reduction led to the corresponding 1,2-diamino- benzenes. Cyclization of the latter with SeCl 4 gave 6-X-4,5,7- trifluoro-2,1,3-benzoselenadiazoles.

Cyclic aryleneazachalcogenenes—VI. Synthesis, crystal and molecular structure of 5,6,7,8-tetrafluoro-1,3,2,4-benzodithiadiazine, a formally antiaromatic stable compound

Abstract 1-Pentafluorophenyl-4-trimethylsilyl-2,4-diaza-1,3-dithia-2,3-butadiene is cyclized by CsF in acetonitrile to 5,6,7,8-tetrafluoro-1,3,2,4-benzodithiadiazine (54% yield), a thermodynamically stable formally antiaromatic 12Π-electron compound having an almost planar molecular geometry, as shown by the X-ray structure analysis data. The crystal and molecular structure of the polyfluorinated derivative appreciably differ from those of its hydrocarbon analogue, 1,3,2,4-benzodithiadiazine.

Organofluorine compounds and fluorinating agents Part 17: Sonochemical-forced preparation of perfluoroalkanals and their use for non-conventional acetalations of carbohydrates

Abstract The homologous 1-iodo-perfluoroalkanes 1a-1c and α,ω-dibromo-perfluoroalkanes 4a, 4b were carbonylated with DMF in the presence of Al/SnCl 2 Al/PbBr 2 under sonication in a short reaction time. The hydrated aldehydes 2a-2c and 5a, 5b respectively were obtained in good yields allowing dehydration to 3a-3c and 6a, 6b . Some of the fluorinated aldehydes were selected as substrates in a Wittig-Horner olefination assisted by ultrasound and in non-conventional acetalations of methyl α- l -rhamnopyranoside ( 9 ). Thus, ( E )-1-perfluorooctyl-2-phenylsulphonyl-ethene ( 8 ) was prepared from 3c and the phosphonate 7 by Wittig-Horner synthesis. Acetalations of 9 were carried out with the aldehydes ( 3a, 3b, 6a ), hydrated aldehydes ( 2a, 2b ), and the aldehyde hemiacetal 12 respectively, in the presence of dicyclohexylcarbodiimide (DCC). In all cases, a selective epimerization was observed at the C-atom 3 of the monosaccharide, i.e. polyfluoroalkylidenated 6-deoxy-α- l -altropyranosides 10,11,13 , and 14 were obtained.

Organofluorine compounds and fluorinating agents part 21: perfluoroalkylidene sugars by non-classical acetalation of pyranoses

Abstract Acetalations of methyl α- d -mannopyranoside (1), methyl 6-O-trityl-α- d -mannopyranoside (5), benzyl α- d -mannopyranoside (14), and methyl β- d -galactopyranoside (17) with perfluoroaldehydes (C4F9CH=O, C6F13CH=O, and C8F17CH=O) in the presence of dicyclohexylcarbodiimide (DCC) lead, under epimerization at the C-atom 3 of the corresponding pyranose moiety, to perfluoroalkylidene derivatives of α- d -altrosides (2–4, 6/7, 15) and of β- d -gulosides (18–20), respectively. After partial deprotection of 3 (or 15) and 18–20, respectively, the liquid crystalline, amphiphilic 3,4-O-perfluorohexylidene- d -altropyranoside (13) and 2,3-O-perfiuoroalkylidene- d -gulopyranosides 24–26 were obtained.

Reactions of polyfluoroarenes with hexamethyldisilazane and with 1,1,1-trimethyl-N,N,-bis(trimethylsilyl) stannaneamine in the presence of caesium fluoride

Abstract Hexamethyldisilazane and 1,1,1-trimethyl- N , N -bis(trimethylsilyl) stannaneamine aminate pentafluoropyridine, octafluorotoluene, pentafluorobenzonitrile, pentafluoronitrobenzene and pentafluorobenzene sulphonyl fluoride in the presence of caesium fluoride with formation of the corresponding perfluorinated aryl amines (ArNH 2 ), diarylamines (Ar 2 NH) and triarylamines (Ar 3 N) (where the amine functions are in positions 4 relative to the arene substituent).

Reactivity of 12π-electron arenothiazines : synthesis and molecular structure of triphenyl[(4,5,6,7-tetrafluoro-1,2λ4δ2,3-benzodithiazol-2-yl)imino]-λ5-phosphane

5,6,7,8-Tetrafluoro-1,3λ4δ2,2,4-benzodithiadiazine 1 adds Ph3P to form triphenyl [(4,5,6,7-tetrafluoro-1,2λ4δ2,3-benzodithiazol-2-yl)imino]-λ5-phosphane 2 whose structure has been identified by X-ray structure analysis.

Facile One-Pot Synthesis of Polyfluorinated Diarylacetonitriles

Abstract Polyfluorinated diarylacetonitriles were obtained by the reaction of polyfluoroaromatic compounds with acetonitrile in the presence of Me3SnN(SiMe3)2 and CsF.