Organometallic fluorine-18 bonds in 18F-radiochemistry

Abstract

Fluorine-18 is by far the most widely exploited radionuclide in PET (positron emission tomography) radiochemistry. The physical half-life of fluorine-18 allows for chemical manipulation within a restricted timeframe, and cyclotron-produced fluoride ion has been widely applied in aliphatic and aromatic nucleophilic radiofluorinations to produce a variety of established radiotracers. Radiotracers have become more structurally complicated to address diverse targets in physiobiological systems. There is therefore an unmet need to complement traditional C-18F bond-forming radiofluorination with new and efficient radiolabeling techniques to tackle the myriad of possible chemical environments. This review discusses recent advances in organometallic fluorine-18 bond creation in 18F-radiochemistry. Although not widely employed, new radiolabeling strategies for constructing boron-18F, silicon-18F, aluminum-18F, and other metal-18F bonds are described in view of their potential use in the development of novel radiopharmaceuticals