Y Zinc Chloride Mediated Synthesis of 1,4-Oxazepines from N-Propargylic -Enaminones


Kelgokmen Y. , Çayan Y., Zora M.

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, ss.7167-7178, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1002/ejoc.201701433
  • Dergi Adı: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
  • Sayfa Sayıları: ss.7167-7178

Özet

An efficient and general method for the synthesis of 1,4-oxazepines is described. When reacted with ZnCl2 in DCM at 40 degrees C or CHCl3 at 61 degrees C, N-propargylic -enaminones undergo 7-exo-dig cyclization to afford 2-methylene-2,3-dihydro-1,4-oxazepines in good to high yields. This cyclization has been found to be general for a diverse range of N-propargylic -enaminones, and proceeds with high efficiency and with broad functional group tolerance. The reactions in refluxing CHCl3 produced 1,4-oxazepines in comparatively short reaction times and with better yields that those obtained in refluxing DCM. This operationally easy method may provide rapid access to a library of functionalized 1,4-oxazepine derivatives of pharmacological interest.