Selectfluor

Beschreibung1-ChloroMethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)(Selectfluor) is a white solid (mp 190 °C), stable in air and to moisture. It is a dicationic salt soluble in cold water or dilute hydrochloric acid. However, it decomposes in dilute sodium hydroxide and reacts with cold DMSO (rapidly and exothermally) and with DMF (slowly on heating). It is moderately soluble in acetonitrile but only slightly soluble in lower alcohols and acetone, which makes the former the solvent of choice. Occasionally, reactions in these solvents were accelerated by adding a small amount of water or trifluoroacetic acid. Bulk quantities of Selectfluor should be stored in a cool, dry place and not heated above 80 °C. Fainzil’berg et al. have measured the reduction potentials of Selectfluor and other N-F compounds. With a positive reduction potential, E1/2 ) 0.33 V, Selectfluor is predicted to be a more reactive fluorinating reagent than, e.g., N-fluorobenzenesulfonimide, with E1/2 ) -1.24 V[1].