The synthesis of fluorinated N-heterocyclic carbenes

  • Azadeh Amirloo

Student thesis: Master of Philosophy


The synthesis of a number of imidazolium salts bearing fluorine-substituted aromatic systems has been reported. 1,3-bis(4-fluorophenyl)imidazolium chloride (26), 1,3-bis(2,4-difluorophenyl)imidazolium chloride (27) and 1,3-bis(2,4,5-trifluorophenyl)imidazolium chloride (33) were prepared via a one-pot condensation involving glyoxal, formaldehyde and the appropriate fluorinated primary amine. It was not possible to prepare and isolate 1,3-bis(pentafluorophenyl)imidazolium chloride in the same way. A series of imidazolium salts were synthesized in which one of the nitrogen substituents contained a polyfluorinated chain; these have been prepared via two different synthetic routes. In the first approach, imidazole was first reacted with polyfluoroalkyl halides (C8F17C2H4I and C4F9C2H4I) to give 1-(polyfluoroalkyl)imidazoles (37 and 38). The second approach involved initial preparation of alkylated imidazoles (R = Pr, Hex, Bu, Oct) and polyfluoroalkyl triflates RFC2H4OSO2CF3 (RF = C6F13, C8F17) resulting in the formation of imidazolium (46 - 49) and methylimidazolium (50 - 52) salts bearing both fluorinated and non-fluorinated chains. Whilst investigating the preparation and use of diaryliodonium salts for the synthesis of N-substituted imidazoles, the single crystal X-ray structure of bis(4-methylphenyl)iodonium triflate (53) was obtained and was found to contain a hydronium triflate, 53.H5O2+OTf -.
Date of Award1 Aug 2016
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorAlan Brisdon (Supervisor) & Robin Pritchard (Supervisor)

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