Veth L *,
Windhorst AD,
Vugts DJ.
Amsterdam UMC, the Netherlands
[
18F]Trifluoroiodomethane – Enabling Photoredox-Mediated Radical [
18F]Trifluoromethylation for Positron Emission Tomography.
Angew. Chem. Int. Ed. 2024;
Keywords
trifluoromethylation - radiochemistry - PET - fluorine-18
Significance
Positron emission tomography (PET) is a molecular imaging technique that visualizes biological processes at the molecular and cellular levels in living organisms. This makes it a powerful tool for early disease diagnosis, monitoring treatment response, and guiding personalized therapy. PET relies on bioactive molecules labeled with a β + emitting nuclide. However, developing new PET imaging agents is often challenging due to synthetic difficulties and the limitations of existing methods when applied to complex molecules. This study presents a method for the radiosynthesis of CF2
18FI and showcases its application in the photoredox-mediated synthesis of novel 18F-labeled α-trifluoromethyl ketones and trifluoromethyl sulfides. This approach effectively expands the toolkit for producing novel PET tracers containing a [18F]CF3 group.
Comment
A method is described for synthesizing and isolating [18F]trifluoroiodomethane. CF2
18FI represents a versatile radiolabelled building block that can, for instance, be used in ruthenium- and photoredox-mediated 18F-trifluoromethylation reactions. The effectiveness of such an approach was demonstrated by producing novel 18F-labeled α-trifluoromethyl ketones and trifluoromethyl sulfides, starting from triisopropylsilyl enol ethers and thiols, respectively. Both procedures are straightforward to perform, tolerate a variety of functional groups, and yield final products with useful molar activity in the range of 8.3–11.1 GBq/µmol. This research sets the foundation for the development of additional 18F-trifluoromethylation methods.