Manganese-catalyzed oxidative benzylic C-H fluorination by fluoride ions.

An efficient protocol for the selective fluorination of benzylic C-H bonds is described. The process is catalyzed by manganese salen complexes and uses nucleophilic fluorine sources, such as triethylamine trihydrofluoride and KF. Reaction rates are sufficiently high (30 min) to allow adoption for the incorporation of (18)F fluoride sources for PET imaging applications.