Strained Ammonium Precursors for Radiofluorinations.

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Organic Chemistry

Background:

• Positron emission tomography (PET) is increasingly used in nuclear medicine.
• Introducing fluorine-18 (t½ = 109.8 min) for radiolabelling is challenging due to harsh reaction conditions.
• Ideal radiolabelling requires mild, physiological conditions, regioselectivity, high yields, and high specific activities.

Purpose of the Study:

• To develop novel methods for mild and efficient introduction of fluorine-18.
• To overcome challenges associated with radiolabelling biologically or pharmacologically active molecules.
• To focus on 2-fluoroethyl and 3-fluoropropyl groups as active sites.

Main Methods:

• Utilizing precursors with ammonium leaving groups.
• Employing strained azetidinium or aziridinium moieties.
• Developing regioselective radiolabelling techniques.

Main Results:

• Demonstrated a convenient and mild introduction of [18F]fluoride.
• Achieved high radiochemical yields.
• Facilitated radiolabelling under conditions suitable for sensitive biomolecules.

Conclusions:

• Precursors with ammonium leaving groups are effective for mild [18F]fluoride introduction.
• This approach overcomes limitations of traditional harsh radiolabelling methods.
• Enables efficient synthesis of 18F-labelled compounds for PET imaging.