Concise design and synthesis of pyridine-fused heterocycles via 6 pi- Azaelectrocyclization process of iminoalkyne derivatives

Sendil K., Keskin S., BALCI M.

TETRAHEDRON, vol.75, no.46, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 75 Issue: 46
  • Publication Date: 2019
  • Doi Number: 10.1016/j.tet.2019.130660
  • Journal Name: TETRAHEDRON
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Pyridine, Pyridine annulation, Propargyl imine, Electrocyclization, Oxazepine, REGIOSELECTIVE SYNTHESIS, BIOLOGICAL EVALUATION, EXPEDIENT ROUTE
  • Middle East Technical University Affiliated: Yes

Abstract

A concise and regioselective approach to the synthesis of pyridine-fused heterocycles and benzoxazepine derivatives was developed. Propargyl imines derived from aromatic aldehydes and propargyl amine underwent 6 pi-electrocyclization reactions at high temperatures in high yields to form pyridine-fused heterocycles. Application of the same methodology to aromatic imines having a hydroxyl group in the ortho position resulted in the formation of (benz)oxazepine derivatives. The formation mechanism of the products was discussed. (C) 2019 Elsevier Ltd. All rights reserved.