A broadly applicable [18F]trifluoromethylation of aryl and heteroaryl iodides for PET imaging.
Huiban M., Tredwell M., Mizuta S., Wan Z., Zhang X., Collier TL., Gouverneur V., Passchier J.
Molecules labelled with the unnatural isotope fluorine-18 are used for positron emission tomography. Currently, this molecular imaging technology is not exploited at its full potential because many (18)F-labelled probes are inaccessible or notoriously difficult to produce. Typical challenges associated with (18)F radiochemistry are the short half-life of (18)F (<2 h), the use of sub-stoichiometric amounts of (18)F, relative to the precursor and other reagents, as well as the limited availability of parent (18)F sources of suitable reactivity ([(18)F]F(-) and [(18)F]F2). There is a high-priority demand for general methods allowing access to [(18)F]CF3-substituted molecules for application in pharmaceutical discovery programmes. We report the development of a process for the late-stage [(18)F]trifluoromethylation of (hetero)arenes from [(18)F]fluoride using commercially available reagents and (hetero)aryl iodides. This [(18)F]CuCF3-based protocol benefits from a large substrate scope and is characterized by its operational simplicity.