Rearrangement of Differentially Protected N ‐Arylhydroxylamines

The rearrangement of a series of N , O ‐difunctionalised N ‐arylhydroxylamines to generate protected 2‐aminophenols has been investigated. N ‐Boc‐ N ‐Aryl‐ O ‐acylhydroxylamines are stable, isolable compounds which rearrange smoothly at temperatures between 110 and 140 °C. The corresponding N ‐Boc‐ N ‐aryl‐ O ‐sulfonylhydroxylamines were not isolated and rearrange to 1,2‐difunctionalised aminophenols at room temperature in excellent yield. Deprotection of either the N ‐ or O ‐substituents under standard conditions allows for further synthetic manipulation of either the aniline or phenol functionality.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)