Direct incorporation of [¹⁸F] into Aliphatic Systems: A promising Mn-catalysed Labelling Technique for PET Imaging

Background: One of the challenges in positron emission tomography (PET) is labelling complex aliphatic molecules. Objective: This study aimed to develop a method of metal-catalysed radiofluorination that is site-selective and works in moderate to good yields under facile conditions. Methods: Herein, we report on the optimisation of an aliphatic C-H to C-¹⁸F bond transformation catalysed by a Mn(porphyrin) complex. Results: The successful oxidation of 11 aliphatic molecules, including progesterone, is reported. Radiochemical Incorporations (RCIs) up to 69% were achieved within 60 min without the need for pre-activation or special equipment. Conclusion: The method features mild conditions (60 °C) and promises to constitute a valuable approach to labelling of biomolecules and drug substances.