18 F-Labeled Aryl-Tracers through Direct Introduction of [ 18 F]Fluoride into Electron-Rich Arenes

Abstract

International audienceRapid and efficient methods using no-carried-added [18F]fluoride as the source of fluorine-18 for nucleophilic aromatic fluorination play an important role in the development of new radiopharmaceuticals for positron emission tomography (PET). Molecules that bear electron-rich aromatic moieties are especially difficult to label by direct single-step nucleophilic no-carrier-added radiofluorination. Classical Balz-Schiemann reaction with its modifications, Wallach reaction and diaryliodonium salts methodology are a few methods to enable this. The present review provides a critical overview of these chemical methods with the emphasis on diaryliodonium salt as precursors for the direct introduction of [18F]fluoride into electron-rich arenes in synthesis of 18F-labeled molecules for PET scanning