Hypervalent Iodine Catalyzed Hofmann Rearrangement of Carboxamides Using Oxone as Terminal Oxidant

Hofmann rearrangement of carboxamides to carbamates using Ozone as an oxidant can be efficiently catalyzed by iodobenzene. This reaction involves hypervalent iodine species generated in situ from catalytic amount of PhI and Oxone in the presence of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) in aqueous methanol solutions. Under these conditions, Hofmann rearrangement of various carboxamides affords corresponding carbamates in high yields.