Concerted [1,3]-Rearrangement in Cationic Cobalt-Catalyzed Reaction of O-(Alkoxycarbonyl)-N-arylhydroxylamines.

O-(Alkoxycarbonyl)-N-arylhydroxylamines were efficiently converted to 2-aminophenol derivatives by cationic cobalt catalysts at 30 °C. The results of 18O-labeling experiments suggested that rearrangement of the alkoxycarbonyl group from the aniline nitrogen to the ortho position proceeded in an unprecedented [1,3] manner.