Convenient Entry to 18 F-Labeled Amines through the Staudinger Reduction

European J Org Chem. 2019 Feb 28;2019(8):1722-1725. doi: 10.1002/ejoc.201801457. Epub 2019 Jan 22.

Abstract

Fluorine-18 possesses outstanding decay characteristics for positron emission tomography (PET) imaging. Therefore, it is ideally suited for clinical applications. As such, improved strategies to incorporate fluorine-18 into bioactive molecules are of utmost importance. Indirect 18F-labeling with amino-functionalized synthons is a convenient and versatile approach to synthesize a broad variety of PET tracers. Herein, we report a method to convert 18F-labeled azides to primary amines by means of the Staudinger reduction. Aliphatic and aromatic 18F-labeled azides were converted into the corresponding amines with high conversion yields. The method was easily automated. From a broader perspective, the applied strategy results in two useful synthons from a single precursor and thus increases the flexibility to label diverse chemical scaffolds with minimal synthetic effort.

Keywords: Amines; Azides; Fluorine; Radiochemistry; Reduction.