This communication describes a method
for the nucleophilic radiofluorination
of electron-rich arenes. The reaction involves the initial C(sp2)–H functionalization of an electron-rich arene with
MesI(OH)OTs to form a (mesityl)(aryl)iodonium salt. This salt is then
used in situ in a Cu-mediated radiofluorination with [18F]KF. This approach leverages the stability and availability of electron-rich
arene starting materials to enable mild late-stage radiofluorination
of toluene, anisole, aniline, pyrrole, and thiophene derivatives.
The radiofluorination has been automated to access a 41 mCi dose of
an 18F-labeled nimesulide derivative in high (2800 ±
700 Ci/mmol) specific activity.