Difluorocarbene-enabled synthesis of ¹⁸F-radiotracers in positron emission tomography

Positron emission tomography (PET) is a preclinical and clinical imaging technique that is extensively used in biomedical research and disease diagnosis to study and visualize biological and physiological processes. The positron emitter used most frequently for PET imaging is fluorine-18 (18F) due to its practical 109.8 min half-life, high yield production on fragile biomedical cyclotrons, and well-established 18F-radiochemistry. Fluorine atom (s) presented in many drugs and biomarkers that provides the opportunity for the development radioligandlabeled with 18F. Summarized in this paper are difluorocarbene (DFC)-enabled 18F-radiosynthesis to introduce [18F]CF3, [18F]CF2 and related motifs in organic molecules and to use them as bioactive radiotracers.