Switchable Oxidative Reactions of N-allyl-2-Aminophenols: Palladium-Catalyzed Alkoxyacyloxylation vs an Intramolecular Diels-Alder Reaction.

The Pd(II)-catalyzed reaction of N-allyl-2-aminophenols in the presence of PhI(OCOR)2 as the oxidant resulted in an alkoxyacyloxylation process, with the formation of functionalized dihydro-1,4-benzoxazines. The reaction performed in the absence of palladium catalyst switched to an intramolecular Diels-Alder reaction (IMDA) pathway, which was the result of an oxidative dearomatization of the 2-aminophenol, nucleophilic addition, and Diels-Alder reaction cascade, highlighting the role of the oxidant as both a nucleophilic donor and an oxidizing agent.