An easy, inexpensive, safe, and effective preparative procedure
to obtain symmetrical diaryliodonium bromides (in 17-88% crude
yields) from various arenes is presented in this paper. A novel
method for the in situ preparation of iodosyl sulfate (Chrétien’s
reagent) is given. Eleven exemplary crude diaryliodonium bromides
were readily oxidatively metathesized with 40% aqueous tetrafluoroboric
acid and 30% aqueous hydrogen peroxide (in boiling acetone,
used both as a solvent and ‘halogen scavenger’)
to give pure diaryliodonium tetrafluoroborates in 15-85% yields.
symmetrical diaryliodonium salts - arenes - sodium metaperiodate - iodosyl sulfate - oxidative anion metatheses