1,1,3,3,3-Pentafluoropropene secondary amine adducts new selective fluorinating agents

Addition of secondary amine SA (dimethylamine DMA, diethylamine DEA, pyrrolidine Pyr, piperidine Pip, morpholine Mor) to pentafluoropropene PFP gives rise to generation of mixtures of two products (1-dialkylamine-1,3,3,3-tetrafluoropropene and N,N-dialkyl-1,1,3,3,3-pentafluoropropylamine) in different ratios. Those reaction mixtures, however, were found to be efficient fluorinating agents replacing hydroxyl groups in alcohols into fluorine. In general, they react with alcohols yielding corresponding fluorides, equimolar amounts of appropriate 3,3,3-trifluoropropionamide and hydrogen fluoride. Aliphatic primary alcohols including octanol and benzylic alcohol yield only alkyl fluorides. The secondary and tertiary alcohols, beside the desired fluorides, give usually considerably amount of alkenes.

Graphical abstractReactions of 1,1,3,3,3-pentafluoropropene (PFP) and secondary amines give mixtures of adducts (PFPDAA), which serve as an efficient fluorinating agent replacing hydroxyl groups in alcohols. Figure optionsDownload full-size imageDownload as PowerPoint slide