Cocatalysis by tetravalent tin compounds in phase-transfer catalyzed fluorination of alkyl halides and sulfonates

Phase-transfer catalyzed fluorination of alkyl halides or sulfonates is co-catalyzed efficiently by triorganotin halides. The cocatalytic action is due to continuous formation of lipophilic hypervalent triorganodifluorostannate anions, which act as fluorinating agents in the organic phase.