Transition metal-free fluorocyclization of unsaturated N-methoxyamides gives cyclic N-methoxyimidates

A new class of fluorinated, cyclic N-methoxyimidates was prepared by the intramolecular fluorocyclization of unsaturated N-methoxyamides. The reaction combined unsaturated amides, a monofluoroiodane, and HFIP as the activator, and this induced an intramolecular fluorocyclization expeditiously at room temperature, giving the products in up to 81% yield in a single step. Two product isomers were chemoselectively produced, depending on whether or not an α-arene substituent was present, in which case the typical reaction sequence was interrupted by a 1,2-phenyl shift prior to the final fluorination step.