Reactions involving fluoride ion. Part 401. Amines as initiators of fluoride ion catalysed reactions

Polyhalogenated heterocyclic compounds. Part 44. Reactions of perfluoro-(4-isopropylpyridine) with oxygen nucleophiles

“…Following the procedures that we described previously, 8 1 was synthesised in good yield, on a large scale, by reaction of pentafluoropyridine with hexafluoropropene using a tertiary amine, tetrakis-(dimethylamino)ethene (TDAE), as a catalyst to generate active fluoride ion (Scheme 1). The reaction was carried out in the absence of solvent making product isolation easy.…”

“…Consequently, only a few examples of reactions involving perfluoro-(alkylheterocycles) have been reported 2,4,5 which include various novel photochemical rearrangements 6 and the formation of remarkably stable valence isomers. 7 Recently, we reported new methodology 8 for the synthesis and isolation of perfluoro-(isopropylheterocycles), which allows efficient scale up. Consequently, a wider exploration of the chemistry of these systems is now feasible.…”

New fluoride ion reagent from pentafluoropyridine

“…Reaction of tertiary amines with perfluorinated alkenes gives ammonium fluoride salts (Scheme 1) which, once formed in situ, catalyse oligomerisation of the fluoroalkene substrate [14]. However, reaction of a tertiary amine with a perfluorinated system, such as pentafluoropyridine, that is susceptible towards nucleophilic attack [15,16] but is not oligomerised in the presence of fluoride ion (Scheme 1), would provide access to fluoride ion reagents that may be useful for carbon-fluorine bond forming reactions.…”

Nucleophilic difluoromethylation and trifluoromethylation using tetrakis(dimethylamino)ethylene (TDAE) reagent

“…Chambers et al [8] employed TDAE in oligomerization and perfluoroalkylation processes (Scheme 7) using fluorinated olefins, such as hexafluoropropene (HFP). In these reactions TDAE should act as a carbon nucleophile producing a valuable fluoride source, soluble in organic solvents.…”