Facile synthesis of R4NF(HFIP)3 complexes from KF and their application to electrochemical fluorination

By exploiting the difference in solubility between KF and KBr in the co-solvent HFIP/CH2Cl2, R4NF(HFIP)3 complexes were synthesised in excellent yields from the ion exchange reaction between KF and R4NBr. The resulting Bu4NF(HFIP)3 was found to have extremely low hygroscopicity and to be effective as a supporting electrolyte and fluorinating reagent in electrochemical fluorination.