One-pot synthesis of iodine-substituted 1,4-oxazepines


ZORA M. , DİKMEN E., KELGÖKMEN Y.

TETRAHEDRON LETTERS, vol.59, no.9, pp.823-827, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 59 Issue: 9
  • Publication Date: 2018
  • Doi Number: 10.1016/j.tetlet.2018.01.048
  • Title of Journal : TETRAHEDRON LETTERS
  • Page Numbers: pp.823-827
  • Keywords: 1,4-Oxazepines, N-Propargylic beta-enaminones, Zinc chloride, Molecular iodine, Electrophilic cyclization, Suzuki-Miyaura reaction, PROPARGYLIC BETA-ENAMINONES, INTRAMOLECULAR CYCLIZATION, PGE(2) ANTAGONIST, POLYSUBSTITUTED PYRROLES, FACILE SYNTHESIS, ANTI-DEPRESSANT, DERIVATIVES, CHEMISTRY, AMOXAPINE, FLUORINE

Abstract

A facile one-pot method for the synthesis of iodine-substituted 1,4-oxazepines is reported. When reacted with ZnCl2 and I-2 in DCM at 40 degrees C, N-propargylic beta-enaminones, prepared by the conjugate addition of propargylamine to alpha,beta-alkynic ketones, underwent 7-exo-dig cyclization by zinc chloride and concomitant reaction with molecular iodine to afford 2-(iodomethylene)-2,3-dihydro-1,4-oxazepines in good to high yields. This cyclization was found to occur with broad scope of substrates and high tolerance of functional groups. The resulting iodine-containing 1,4-oxazepines can be further elaborated to more complex structures by subsequent cross-coupling reactions, which may provide a platform for biological studies. (C) 2018 Elsevier Ltd. All rights reserved.