Substituent and solvent effects on the reactions of organoboronic acids with fluoride

The introduction of an electron-withdrawing substituent or a substituent pr otonated to be positively charged and potentially involved in hydrogen bond ing enhances the reactivities of phenylboronic acids with fluoride. The use of a 60% aqueous MeOH medium suppresses the formation of the negatively ch arged species, irrespective of whether their structures are trigonal or tet rahedral, but enhances the overall reactivity because of less solvation of fluoride.