Fluorinated Tertiary Alcohols and Alkoxides from Nucleophilic Trifluoromethylation of Carbonyl Compounds

Article abstract of DOI:10.1021/jo00030a018

(CH3)3SiCF3 reacts with fluoro ketones in the presence of excess KF in CH3CN to produce alkoxides derived from formal addition of CF3(1-) to the carbonyl carbon.These alkoxides may be isolated as such or acidified to the corresponding alcohols.Ketones to which this technique was applied include (CF3)2C=O, CF3C(O)CF2Cl, CF3C(O)CF2H, and <(CF3)2CF>2C=O.The last compound reacts with replacement of one of its perfluoroisopropyl groups by CF3.With 2 equiv of TMS-CF3, the acid fluorides RC(O)F (R = CF3CF2, n-C3F7, n-C7F15) yield products of the form RC(CF3)2OX (X = K, H) due to both substitution and addition of CF3 at the carbonyl.Similarly, F2C=O with 3 equiv of TMS-CF3 provides a novel and high-yield synthesis of the perfluoro-tert-butoxide group.Phosgene does not appear to react directly with the TMS-CF3/KF system, but is converted first to CF2C=O.The intermediate ketone CF3CF2C(O)CF3 is observed in reactions of equimolecular amounts of CF3CF2C(O)F and TMS-CF3.