Efficient Synthesis of 4H-3,1-Benzoxazine Derivatives via One-Pot Sequential Passerini-Azide/Palladium-Catalyzed Azide–Isocyanide Coupling/Cyclization Reaction

Abstract

A new, one-pot method for the synthesis of 4H-3,1-benzoxazine derivatives has been developed. The Passerini-azide reactions of 2-azidobenzaldehydes, trimethylsilyl azide, and isocyanides produced azide intermediate without separation, which then reacted with isocyanides to give 4H-3,1-benzoxazine derivatives via a tandem one-pot palladium-catalyzed azide–isocyanide coupling/cyclization reaction in moderate to good yields.