Nucleophilic Trifluoromethoxylation of Benzyl Bromides via Carbonyl Diimidazole

An operationally simple nucleophilic trifluoromethoxylation protocol via an inexpensive, commercially available and bench stable reagent, carbonyl diimidazole and AgF is presented. Mechanistic studies are performed to reveal that this method does not proceed through the conventional trifluoromethoxide anion pathway that generates toxic difluorophosgene as an intermediate.