Hexafluoroisopropanol (HFIP)-prompted rearrangement of N-phenoxysulfonamides for the direct assembly of ortho-sulfonamide phenols: A combined experimental and computational study

ortho-Sulfonamide phenols represent a class of attractive structural motifs in medicinal and synthetic chemistry. Herein an efficient metal-free rearrangement reaction has been developed for the construction of ortho-sulfonamide phenols via HFIP-prompted intramolecular sulfonamide group 1,3-migration. This protocol features mild reaction conditions, broad functional group compatibility and good regioselectivity. Combined experimental mechanistic study and detailed DFT calculations clarified the crucial role of HFIP molecules in facilitating this reaction, and the unique hydrogen bond network had been deduced to account for the observed reactivity.