[11C]Carbonyl Difluoride—a New and Highly Efficient [11C]Carbonyl Group Transfer Agent

• Published in: Angewandte Chemie International Edition 2020-04, Vol.59 (18), p.7256-7260
• Main Authors: Jakobsson, Jimmy E., Lu, Shuiyu, Telu, Sanjay, Pike, Victor W.
• Format: Article
• Language: English
• Subjects: Aldehydes - chemical synthesis; Aldehydes - chemistry; Carbon monoxide; Carbon Radioisotopes; carbon-11; Carbonyl compounds; carbonyl difluoride; Carbonyl groups; Carbonyls; Difluorides; Fluorides; heterocycles; Heterocyclic Compounds - chemistry; isotopic labeling; Labeling; Molecular Structure; PET radiochemistry; Positron-Emission Tomography; Radioactive tracers; Radiochemistry; Radiopharmaceuticals - chemical synthesis; Radiopharmaceuticals - chemistry; Room temperature; Substrates
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201915414

Herein, the synthesis and use of [11C]carbonyl difluoride for labeling heterocycles with [11C]carbonyl groups in high molar activity is described. A very mild single‐pass gas‐phase conversion of [11C]carbon monoxide into [11C]carbonyl difluoride over silver(II) fluoride provides easy access to this new synthon in robust quantitative yield for labeling a broad range of cyclic substrates, for example, imidazolidin‐2‐ones, thiazolidin‐2‐ones, and oxazolidin‐2‐ones. Labeling reactions may utilize close‐to‐stoichiometric precursor quantities and short reaction times at room temperature in a wide range of solvents while also showing high water tolerability. The overall radiosynthesis protocol is both simple and reproducible. The required apparatus can be constructed from widely available parts and is therefore well suited to be automated for PET radiotracer production. We foresee that this straightforward method will gain wide acceptance for PET radiotracer syntheses across the radiochemistry community. Ocean′s Eleven: The synthesis and use of [11C]carbonyl difluoride for labeling heterocycles is described. Labeling reactions with [11C]COF2 are very mild and proceed in high yields in short reaction times at room temperature in a wide range of solvents. The radiosynthesis protocol is simple and easily implemented.