Redox‐Neutral Selenium‐Catalysed Isomerisation of para‐Hydroxamic Acids into para‐Aminophenols

Abstract A selenium‐catalysed para ‐hydroxylation of N ‐aryl‐hydroxamic acids is reported. Mechanistically, the reaction comprises an N−O bond cleavage and consecutive selenium‐induced [2,3]‐rearrangement to deliver para ‐hydroxyaniline derivatives. The mechanism is studied through both 18 O‐crossover experiments as well as quantum chemical calculations. This redox‐neutral transformation provides an unconventional synthetic approach to para ‐aminophenols.