Synthesis of aryl-CHFCF3 systems.

The fluorine-containing functional group Ar-CFHCF3 is potentially useful within the pharmaceutical, agrochemical and polymer industries if synthetic methodology is available for the synthesis of these systems. Here, a new general synthetic pathway for the synthesis of 1-aryl-1,2,2,2-tetrafluoroethanes starting from either benzaldehyde or 3-pyridinecarboxaldehyde derivatives is presented. Reactions of aldehydes with CF3SiMe3 and a catalyst of TBAF (tetrabutylammonium fluoride) and then DAST (diethylaminosuphur trifluoride) were generally very efficient for a range of substrates bearing electron donating/ withdrawing substituents on the aromatic ring.