Activation of the hypervalent fluoroiodane reagent by hydrogen bonding to hexafluoroisopropanol

Hexafluoroisopropan-2-ol (HFIP) is an excellent solvent for promoting fluorinations with the hypervalent fluoroiodane reagent 1 and crucially, it removes the need for transition metals or TREAT-HF activators. The fluoroiodane reagent 1 was used in HFIP to monofluorinate 1,3-ketoesters and to fluorocyclise unsaturated carboxylic acids in excellent yields under mild reaction conditions.