A cooperative allylic fluorination: combination of nucleophilic and electrophilic fluorine sources

A one step, regioselective allylic fluorination of alkenes is reported in which electrophilic and nucleophilic sources of fluorine act synergistically to afford rearranged allylic fluorides over alternative vicinal dihalides. The reaction occurs under exceptionally mild conditions and without need for prefunctionalization or transition metal catalysts. The fluorination of cyclic alkenes and monoterpenes is highlighted, and preliminary mechanistic experiments reveal that dual (radical and ionic) pathways operate simultaneously.