General and Highly Efficient Syntheses of m-Fluoro Arenes Using Potassium Fluoride-Exchange Method

Tetraphenylphosphonium bromide was found to be a suitable catalyst for the reaction of m-nitroaryl derivatives carrying cyano, nitro, chlorocarbonyl, trifluoromethyl, and chlorosulfonyl groups with potassium fluoride in the presence of a stoichiometric amount of phthaloyl dichloride, giving the corresponding m-fluoro aromatic derivatives in good yields. The catalyst was also found to be efficient for the fluorodesulfonylation of m-(fluorosulfonyl)aryl derivatives to afford m-fluoro arenes by the use of a reaction-distillation technique.