Gold-Catalyzed Intramolecular Cyclization of <i>N</i>‑Propargylic β‑Enaminones for the Synthesis of 1,4-Oxazepine Derivatives

An efficient and mild one-pot, gold-catalyzed intramolecular cyclization of <i>N</i>-propargylic β-enaminones has been achieved for the generation of 1,4-oxazepine derivatives. This synthetic transformation tolerates a range of substituted <i>N</i>-propargylic β-enaminones in moderate to good yields.