[18F]Fluorophenyl organometallics as intermediates of no-carrier-added 18F-fluoroarylation reactions

Based on the recent availability of no-carrier-added (n.c.a.) 1-bromo-4-[18F]fluorobenzene with high radiochemical yield, the 4-[18F]fluorophenyl compounds of lithium, sodium and magnesium can now also effectively be prepared. Thus, [18F]fluoroarene reagents with a nucleophilic reaction centre are available and suitable among others for the formation of [18F]fluorophenyl compounds with electron donating substituents in the radiosynthesis of 18F-labelled complex organic structures. For these arylation reactions, however, the presence of macroscopic amounts of a haloarene as co-reactant is necessary with all n.c.a. [18F]fluorophenyl metallics. The 18F-fluoroarylation was verified for examples of aryl-carbon, -silicon, -sulphur, and -nitrogen bond formation with radiochemical yields of 20–25% related to the starting radioactivity of [18F]fluoride.