No abstract

Various N,N-diallylic amines and amides were rapidly converted to fluorinated piperidines after a novel cyclisation/fluorination reaction in superacid HF-SbF5.

The novel cyclization/fluorination reaction of N-dienes in superacid was extended to substituted substrates. The influence of the substitution on superelectrophilic character of dicationic intermediates was shown and its dramatic effect on the synthesis of fluoropiperidines was studied. On the basis of new dicationic alpha-chloronium ammonium intermediates, starting from halogen-substituted dienes, high-valued fluorinated piperidines were synthesized.

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Superacid. -It is found that the nature of substituents on the nitrogen atom and C=C double bond has strong influence on the outcome of title reaction. Fluorinated pyrrolidines, 3-and 4-fluoropiperidines as well as tetrahydroisoquinolines are available. In some cases, no cyclization takes place. -(VARDELLE, E.; MARTIN-MINGOT, A.; JOUANNETAUD, M.-P.; BACHMANN, C.; MARROT, J.; THIBAUDEAU*, S.; J.