Metal free electrophilic fluoro-cyclization of unsaturated N-hydroxy- and N-acetoxyamides with N–F reagents
作者:Lyudmila F. Lourie、Yurii A. Serguchev、Anton V. Bentya、Maxim V. Ponomarenko、Eduard B. Rusanov、Michail V. Vovk、Andrey A. Fokin、Nikolai V. Ignat’ev
DOI:10.1016/j.jfluchem.2015.04.011
日期:2015.11
Metal-free electrophilic fluoro-cyclizations of the respective unsaturated N-hydroxy- and N-acetoxyamides under action of the 1-chloromethy1-4-fluoro-1,4-diazoniabicyclo[2 2 2]octane bis(tetrafluoroborate) (F-TEDA-BF4; trade name SelectfluorTM) and F-TEDA-FAP (FAP = [(C2F5)(3)PF3](-)) were carried out in organic solvents and ionic liquid 1-ethy1-3-methylimidazolium triflate. The fluoro-cyclization of trans-N-acetoxy-4-phenylbut-3-enamide (1), trans-N-hydroxy-4-phenylbut-3-enamide (2), N-hydroxy4-phenylpent-4-enamide (3) and N-acetoxy-4-phenylpent-4-enamide (4) results in the formation of cyclic imidates. The influence of the nature of fluorinating reagent and solvent on the stereoselectivity of fluoro-cyclization is discussed. (C) 2015 Elsevier B.V. All rights reserved.