Synthesis of Aryl Fluorides Using Electrophilic N-F Reagents

1-Fluoro-2,4,6-trimethylpyridinium tetrafluoroborate (1) is utilized for synthesis of aryl fluoride derivatives. 1 is treated with an aryl Grignard reagent to afford corresponding aryl fluorides in moderate yields. The reactions are tolerance to electron-donating and electron-withdrawing groups, as well as pyridine derivatives. Furthermore, aryl boronic acids are fluorinated by 1 and silver fluoride under copper catalyst. The reaction is applicable to a variety of boronic acids with aldehydes, ketones and esters. Therefore, the method is expected to be used in the scale-up synthesis of pharmaceutical intermediates and late-stage fluorination of pharmaceuticals.