Processes and reaction mixtures including non-aqueous solvent mixtures are presented. Non-aqueous solvent mixtures including fluoride salt and non-aqueous solvent combinations are provided that possess high fluoride ion concentrations useful for a range of applications, including organic synthesis. Further non-aqueous solvent mixtures are provided including a salt possessing a non-fluoride anion and a non-aqueous solvent that, when contacted with aqueous fluoride-containing reagents, extract fluoride ions to form non-aqueous fluoride-ion solutions possessing high fluoride-ion concentrations. The salts include an organic cation that does not possess a carbon in the β-position or does not possess a carbon in the β-position having a bound hydrogen. This salt structure facilitates its ability to be made anhydrous without decomposition. Example anhydrous fluoride salts include (2,2-dimethylpropyl)trimethylammonium fluoride and bis(2,2-dimethylpropyl)dimethylammonium fluoride. The combination of these fluoride salts with at least one fluorine-containing non-aqueous solvent (e.g., bis(2,2,2-trifluoroethyl)ether; (BTFE)) promotes solubility of the salt within the non-aqueous solvents.