Abstract Functionalization of mono-and di-substituted benzene derivative with CsSO 4 F has been modulated by substituents on the benzene ring. α-Hydroxyalkylbenzenes, with a deactivated ring, were oxidized to phenones, while fluorodealkylation was achieved in high yield when electron-donating groups were present in a para position. Electron-withdrawing substituents favoured chain fluorofunctionalization in alkylbenzenes, while ring ...