Unexpected reactivity of cyclic perfluorinated iodanes with electrophiles

We have found that cyclic perfluorinated iodanes react with electrophiles (E+= Br, Cl, F, I) to afford perfluorinated E-R-F compounds. This reactivity is unexpected since cyclic perfluorinated iodanes are considered as electrophilic reagents that normally react with nucleophiles (e.g. Nu(-) = SR, OR) to afford Nu-R-F products. The utility of this new transformation is demonstrated for a [F-18]CF3CF2- containing compound which was prepared from [F-18]XeF2 obtained from cyclotron produced [F-18]fluoride.