TFFH is an air-stable, nohygroscopic solid, has been shown to act as a coupling reagent that proceeds via in situ conversion to an acid fluoride.

CAS: 164298-23-1

Synonym: Fluoro-N,N,N′,N′-tetramethylformamidiniumhexafluorophosphate




Molecular Formula


Molecular Weight

264.12 [gr/mol]


White to off-white crystalline powder

Storage Conditions

Store in a cool place


  • When TFFH is used, the active specie is the acid fluoride, which is very reactive due to high electronegativity of the F and it small size.
  • TFFH was reported as a convenient reagent for the preparation of isothiocyanates from the corresponding primary amines in the presence of carbon disulfide.
  • TFFH is a useful reagent for the conversion of carboxylic acids into anilides, hydrazides as well as acyl azides.
  • TFFH is substitute for the corrosive cyanuric fluoride and suitable for the preparation of acyl fluorides even when unsaturated double bonds, hydroxyl groups, or aromatic rings are present.
  • TFFH is especially useful for the two amino acids histidine and arginine since the corresponding amino acid fluorides are not stable toward isolation or storage.


  • Tetramethylfluoroformamidinium Hexafluorophosphate: A Rapid-Acting Peptide Coupling Reagent for Solution and Solid Phase Peptide Synthesis
    L. A. Carpino and A. El-Faham J. Am. Chem. Soc., 1995117 (19), 5401–5402.
  • Tetramethylfluoroformamidinium hexafluorophosphate (TFFH)/benzyltriphenylphosphonium dihydrogen trifluoride (PTF): a unique reagent for the conversion of carboxylic acids to the corresponding alcohols as well as hydroxamic acids
    A. El-Faham, S. N. Khattab, M. Abdul-Ghani. ARKIVOC, 2006, xiii, 57-63.
    Read Article
  • Utilization of N,N,N’,N’-Tetrafluoroformamidinium hexafluorophosphate (TFFH) in peptide and organic synthesis
    El-Faham, S. N. Khattab Synllet, 2009, 6, 0886–0904.
    Read Article

Request an Information or Quotation