Recent developments and trends in 18F-radiochemistry:: Syntheses and applications

In this short review we describe recent methods and novel trends for the introduction of fluorine-18 into molecules which in turn are intended to serve as imaging agents for the in vivo imaging modality positron emission tomography (PET). These F-18-labeling schemes are based on enzymatic fluorination, the use of ionic liquids, protic solvents acting as catalysts, application of click chemistry, thiol-reactive labeling agents for peptide and protein labeling and the most recent introduction of non-classical radiochemistry based on organo-phosphorous, organo-boron and organo-silicon radiochemistry. The latter approach for the first time introduced an F-18-chemistry characterized by high selectivity and unique efficiency making complicated work-up procedures obsolete.