Electrochemical Flash Fluorination and Radiofluorination.

A new method for rapid late-stage fluorination using the cation pool technique is presented. Fluorination and no-carrier-added radiofluorination of methyl (phenylthio) acetate, methyl 2-(methylthio) acetate, and methyl 2-(ethylthio) acetate were performed. The carbocations formed through electrochemical oxidation were stabilized by using a divided electrochemical cell and 2,2,2-trifluoroethanol (TFE) as the solvent at -20 °C. At the end of electrolysis, either stable-isotope [19F]fluoride or no-carrier-added radioactive [18F]fluoride was added to the reaction mixture to form the fluorinated or radiofluorinated product.