Collect. Czech. Chem. Commun. 2002, 67, 1296-1304

Fluoride-Catalyzed Nucleophilic Perfluoroalkylations of Acetylenic Ketones or Aldehydes

Sudha Manandhar, Rajendra P. Singh and Jean'ne M. Shreeve*

Department of Chemistry, University of Idaho, Moscow, ID 83844-2343, U.S.A.


Reactions of 4-phenylbut-3-yn-2-one (1a) and phenylpropynal (1b) with trimethyl(perfluoroalkyl)silanes (Me3SiRf) (Rf = CF3, C2F5, n-C6F13, n-C7F15, n-C8F17) in the presence of catalytic amounts of cesium fluoride (CsF) have been studied. Compounds 1a, 1b were reacted with 0.5 equivalent excess of Me3SiRf in ethylene glycol dimethyl ether (monoglyme) at 25 °C for Rf = CF3, C2F5 and at 50 °C for Rf = n-C6F13, n-C7F15, n-C8F17 to give the corresponding perfluoroalkylated alcohols in good yields after acid hydrolysis. The new compounds were characterized by IR, NMR (1H, 19F, 13C), MS and elemental analysis. In these reactions, tetrabutylammonium fluoride (TBAF) is also effective as the fluoride catalyst. The alcohols with CF3 or C2F5 are viscous liquids whereas those with n-C6F13, n-C7F15 or n-C8F17 are solids. They are soluble in common organic solvents and stable to air and moisture.

Keywords: Fluoride; Nucleophilic additions; Perfluoroakylations; Ketones; Aldehydes; Alkynes; Trimethyl(perfluoroalkyl)silanes.

References: 41 live references.