Synthesis of Geminal Difluorides by Oxidative Desulfurization−Difluorination of Alkyl Aryl Thioethers with Halonium Electrophiles in the Presence of Fluorinating Reagents and Its Application for<sup>18</sup>F-Radiolabeling
from alkyl aryl thioethers by a new oxidative desulfurization−difluorination protocol with the reagents combination of 1,3-dibromo-5,5-dimethylhydantoin (DBH) as an oxidizer and pyridine·9HF (Py·9HF) as a fluoride source. The reaction proceeds via a fluoro-Pummerer-type rearrangement followed by an oxidative desulfurization−fluorination step. Starting from α-fluorinated thioethers, this reaction is