Benzylic Fluorination of Aza-Heterocycles Induced by Single-Electron Transfer to Selectfluor.
Kelley E DanahyJulian C CooperJeffrey F Van HumbeckPublished in: Angewandte Chemie (International ed. in English) (2018)
A selective and mild method for the benzylic fluorination of aromatic azaheterocycles with Selectfluor is described. These reactions take place by a previously unreported mechanism, in which electron transfer from the heterocyclic substrate to the electrophilic fluorinating agent Selectfluor eventually yields a benzylic radical, thus leading to the desired C-F bond formation. This mechanism enables high intra- and intermolecular selectivity for aza-heterocycles over other benzylic components with similar C-H bond-dissociation energies.