Exchange of halogen for fluorine in reactions of vicinal dihalopolyfluoroalkanes with cesium fluoride

The authors found that under certain relatively mild conditions, certain vicinal dihalopolyfluoroalkanes and related compounds react with CsF also in aprotic dipolar solvents (MeCN, diglyme), and give products of the exchange of one of the halogens for fluorine. The F-19 NMR spectra were measured on the Perkin-Elmer R-32 spectrometer with reference to CF3COOH as external standard. In vicinal dihalopolyfluoroalkanes and related compounds, an exchange of the halogen for fluorine takes place by the action of CsF, according to an ionic elimination-addition chain mechanism