1. Sequential Ir/Cu-Mediated Method for the Meta -Selective C-H Radiofluorination of (Hetero)Arenes.
- Author
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Wright JS, Sharninghausen LS, Preshlock S, Brooks AF, Sanford MS, and Scott PJH
- Subjects
- Fluorine Radioisotopes, Halogenation, Molecular Structure, Boronic Acids chemistry, Copper chemistry, Esters chemistry, Fluorides chemistry, Iridium chemistry, Quaternary Ammonium Compounds chemistry
- Abstract
This article describes a sequential Ir/Cu-mediated process for the meta- selective C-H radiofluorination of (hetero)arene substrates. In the first step, Ir-catalyzed C(sp
2 )-H borylation affords (hetero)aryl pinacolboronate (BPin) esters. The intermediate organoboronates are then directly subjected to copper-mediated radiofluorination with [18 F]tetrabutylammonium fluoride to afford fluorine-18 labeled (hetero)arenes in high radiochemical yield and radiochemical purity. This entire process is performed on a benchtop without Schlenk or glovebox techniques and circumvents the need to isolate (hetero)aryl boronate esters. The reaction was automated on a TracerLab FXFN module with 1,3-dimethoxybenzene and a meta- tyrosine derivative. The products, [18 F]1-fluoro-3,5-dimethoxybenzene and an18 F-labeled meta- tyrosine derivative, were obtained in 37 ± 5% isolated radiochemical yield and >99% radiochemical purity and 25% isolated radiochemical yield and 99% radiochemical purity, and 0.52 Ci/μmol (19.24 GBq/μmol) molar activity ( Am ), respectively.- Published
- 2021
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