Rapid <sup>18</sup>F‐ and <sup>19</sup>F‐Difluoromethylation through Desulfurative Fluorination of Transient N‐, O‐, and C‐Linked Dithioles
Josiah J. Newton, Gökçe Engüdar, Alan J. Brooke, Matthew B. Nodwell, Holly Horngren‐Rhodes, Rainer E. Martin, Paul Schaffer, Robert Britton, Chadron M. Friesen
Abstract
Abstract The difluoromethyl group plays an important role in modern medicinal and agrochemistry. While several difluoromethylation reagents have been reported, these typically rely on difluoromethyl carbenes or anions, or target specific processes. Here, we describe a conceptually unique and general process for O−H, N−H and C−H difluoromethylation that involves the formation of a transient dithiole followed by facile desulfurative fluorination using silver(I) fluoride. We also introduce the 5,6‐dimethoxy‐1,3‐benzodithiole (DMBDT) function, which undergoes sufficiently rapid desulfurative fluorination to additionally support 18 F‐difluoromethylation. This new process is compatible with the wide range of functional groups typically encountered in medicinal chemistry campaigns, and the use of Ag 18 F is demonstrated in the production of 18 F‐labeled derivatives of testosterone, perphenazine, and melatonin, 58.0±2.2, 20.4±0.3 and 32.2±3.6 MBq μmol −1 , respectively. We expect that the DMBDT group and this 18 F/ 19 F‐difluoromethylation process will inspire and support new efforts in medicinal chemistry, agrochemistry and radiotracer production.