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

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