Synthesis of Polyfluorinated Nitrogen‐Containing Heterocycles from Hemifluorinated Enones or Organofluorosilicon Building Blocks as Synthetic Equivalents

Abstract

A series of polyfluorinated heterocycles has been prepared by heterocyclisation of hemifluorinated enones or organofluorosilicon synthetic equivalents with different bis(nucleophiles). These polyfluorinated building blocks were obtained by treatment of acylsilanes with perfluoro organometallic reagents. The method is general and has been applied to aliphatic, aromatic and carbohydrate derivatives, to give oxazolidines, imidazolidines, benzodia‐ and ‐thiazepines, quinolines and pyrimidines bearing both a fluorine atom and a perfluoroalkyl group in vicinal positions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Benzo[1,5]thiazepine: Synthesis, Reactions, Spectroscopy, and Applications

“…It was therefore concluded that this is a product resulting from one molecule of 365 B reacting with two molecules of 366 b . The NMR spectrum of this compound does not show an AMX signal attributable to the three protons on the seven membered ring but instead gives a signal corresponding to a 2H doublet with a coupling constant of 7 Hz at l. 46 When the reaction of 365 A and 366 a was carried out at reflux temperature, a low melting-point crystalline solid was obtained in addition to a small amount of the expected 367 Aa . The IR spectrum of this compound showed absorption at 1676 cm −1 ; while the band at 1750 cm −1 , which is the typical carbonyl absorption for a -lactam, is not present.…”

“…Condensation of o-aminothiophenol, with the enones 179 (or 180 or 181) provided the corresponding benzothiazepines 182a-c in good yields. In the carbohydrate series, the 1,5-benzothiazepines 182c was obtained as an epimeric mixture (D-xylo/L-arabino in a 85 : 15 ratio), indicating that a further C-4 epimerisation had occurred during the formation of the heterocycle [44][45][46][47] (Scheme 36).…”

“…Therefore, upon heating the benzothiazepine 182a to 120 ∘ C, an efficient extrusion of sulfur atom for the benzothiazepine with the aromatic substituent was observed and gave 3-fluoro-2-(4-fluorophenyl)-4-(perfluorobutyl)quinoline 394a in 80% yield [44][45][46][47] (Scheme 71).…”

“…The proton spectra (DMSO-6 ) of (E)-4,4 -methylenebis(2-((E)-4-phenyl-2,3-dihydrobenzo [1,5]thiazepin-2-yl)phenol) 114a and bis(3-phenyl-7-((E)-4-phenyl-2,3-dihydrobenzo [1,5] [44][45][46][47].…”

Synthesis of Fluorinated Homo-C-Nucleoside Analogues from New Carbo­hydrate-Derived Acylsilanes

“…8 The synthesis of such heterocycles linked to a carbohydrate moiety was also exemplified from carbohydrate-derived acylsilanes. 7,8 In order to form fluorinated homo-C-nucleoside analogues, we performed the synthesis of new compounds bearing an acylsilane function linked to the anomeric carbon atom via a methylene group. This paper is devoted to the account of this synthetic work and to the application of these new carbohydrate derived acylsilanes to the synthesis of fluorinated homo-C-nucleoside analogues.…”