Copper-Catalyzed Synthesis of Fused Imidazopyrazine N-Oxide Skeletons

Taşdemir V., Kuzu B., Tan M., Genç H., Menges N.

SYNLETT, vol.30, no.3, pp.307-310, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 3
  • Publication Date: 2019
  • Doi Number: 10.1055/s-0037-1610859
  • Journal Name: SYNLETT
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.307-310
  • Keywords: alkynes, cyclization, copper catalysis, imidazopyrazine oxides, oximes, INDEPENDENT CHEMICAL-SHIFTS, METAL-FREE, AROMATICITY, CYCLIZATION, STRATEGY
  • Van Yüzüncü Yıl University Affiliated: Yes


N-Propargyl-2-aroylimidazoles synthesized and converted into the corresponding ketoximes. Under various conditions, several mono- and diketoxime imidazole derivatives were formed by converting the carbonyl or carbonyl and propargyl groups into oxime groups. N-Propargyl monooxime imidazole derivatives were cyclized by treatment with CuI to give various imidazopyrazine N-oxides. Several copper salts, such as CuOAc, CuSO (4) , and CuOTf, formed the same cyclization product. This cyclization reaction occurred only in the presence of Cu(I) or Cu(II) salts; other transition metals such as Au, Ag, In, and Fe did not yield cyclic products. The nucleus-independent chemical shift method was used to calculate the aromaticity of the bicyclic rings.