FLUORIDE-CATALYZED NUCLEOPHILIC PERFLUOROALKYLATIONS OF ACETYLENIC KETONES OR ALDEHYDES

摘要

Reactions of 4-phenylbut-3-yn-2-one (la) and phenylpropynal (lb) with trimethyl-(perfluoroalkyl)silanes (Me_3SiR_f) (R_f = CF_3, C_2F_5, n-C_6F_(13), n-C_7F_(15), n-C_8F_(17) in the presence of catalytic amounts of cesium fluoride (CsF) have been studied. Compounds la, lb were reacted with 0.5 equivalent excess of Me_3SiR_f in ethylene glycol dimethyl ether (monoglyme) at 25 deg C for R_f = CF_3, C_2F_5 and at 50 deg C for R_f = n-C_6F_(13), n-C_7F_(15), n-C_8F_(17) to give the corresponding perfluoroalkylated alcohols in good yields after acid hydrolysis. The new compounds were characterized by IR, NMR (~1H, ~(19)F, ~(13)C), MS and elemental analysis. In these reactions, tetrabutylammonium fluoride (TBAF) is also effective as the fluoride catalyst. The alcohols with CF_3 or C_2F_5 are viscous liquids whereas those with n-C_6F_(13), n-C_7F_(15) or n-C_8F_(17) are solids. They are soluble in common organic solvents and stable to air and moisture.