Direct Organocatalytic α-Fluorination of Aldehydes and Ketones

Abstract
The first organocatalytic direct α-fluorination of aldehydes and ketones employing Selectfluor {1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)} as the fluorine source is reported. (S)-Proline and related derivatives act as organocatalysts to give the corresponding α-fluoroaldehydes and a-fluoroketones in moderate to good yields (47-78%). The asymmetric ­inductions are still low (ee ≤ 36%).