C-H Labeling with [¹⁸F]Fluoride: An Emerging Methodology in Radiochemistry

Area of Science:

• Radiochemistry
• Nuclear Medicine
• Organic Synthesis

Background:

• Fluorine-18 is the primary radioisotope for positron emission tomography (PET) imaging.
• Current PET agent synthesis often relies on less efficient, multi-step precursor functionalization.
• C-H bond radiolabeling offers a more direct route to introduce fluorine-18, simplifying precursor requirements.

Purpose of the Study:

• To review recent advancements in fluorine-18 C-H radiolabeling techniques.
• To discuss the advantages and limitations of these methods for preclinical and clinical applications.
• To identify barriers to adoption and future research directions in C-H radiofluorination.

Main Methods:

• Focus on nucleophilic [18F]fluoride sources and their application in C-H bond functionalization.
• Comparison of C-H radiolabeling strategies with established methods like S_NAr and S_N2 radiofluorinations.
• Analysis of recent developments in C-H radiofluorination and radiofluoroalkylation.

Main Results:

• Multiple high-utility nucleophilic C-H radiolabeling techniques have emerged in the last decade.
• Despite advantages, clinical adoption of C-H radiolabeling for PET agents remains slow.
• C-H radiofluorination holds potential to improve the efficiency and scope of PET agent production.

Conclusions:

• C-H radiofluorination and radiofluoroalkylation can potentially enhance and replace current PET agent synthesis methods.
• Addressing limitations in C-H labeling strategies is crucial for their broader implementation.
• Further development is needed to overcome barriers and facilitate the expedited production of PET agents for disease staging and drug development.