Allyl, epoxy and glycosyl perfluoroimidates. One-pot preparation and reaction

The one-pot preparation of allyl, epoxy and glycosyl perfluoroimidates and their reaction are described. Volatile perfluoronitriles were generated from perfluoroamides with an ‘activated’ dimethyl sulfoxide (DMSO) species at −78°C. Allyl, epoxy and glycosyl perfluoroimidates were prepared in 44–92% yield following in situ nucleophilic addition of alcohol and sugar derivatives to nitriles. The obtained trifluoroacetimidates were more stable than the trichloro analogue and were easily purified by SiO2 column chromatography and/or distillation. The 3,3-sigmatropic rearrangement of allylic analogues, acid-catalyzed cyclization of the epoxy analogues and glycosylation of sugar analogues were studied comparing with their corresponding trichloroacetimidates. The trifluoroacetimidates were considerably less reactive than trichloroacetimidates due to their electron-withdrawing substituents on the imidate carbon.