Mild Fluorination of Chloropyridines with in Situ Generated Anhydrous Tetrabutylammonium Fluoride

This paper describes the fluorination of nitrogen heterocycles using anhydrous NBu₄F. Quinoline derivatives as well as a number of 3- and 5-substituted pyridines undergo high-yielding fluorination at room temperature using this reagent. These results with anhydrous NBu₄F compare favorably to traditional halex fluorinations using alkali metal fluorides, which generally require temperatures of ≥100 °C.