Synthesis of Indolizines by Dimerization of N-Propargylated Pyrroles via Allene Intermediates


Kuzu B., Gul S., Tan Uygun M., Mengeş N., BALCI M.

CHEMISTRYSELECT, cilt.6, sa.9, ss.2366-2372, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 6 Sayı: 9
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1002/slct.202100045
  • Dergi Adı: CHEMISTRYSELECT
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier
  • Sayfa Sayıları: ss.2366-2372
  • Anahtar Kelimeler: allene, indolizine, intermolecular cyclization, radical reaction, radical scavenger
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

Ten different N-propargyl pyrrole derivatives having various substituents at the C-2 position were synthesized. These derivatives were converted into indolizine derivatives by the [2+2] cycloaddition reaction of pyrrole N-allene, forming in situ, by heating in PrOH in basic medium. The structures were characterized by NMR and X-ray crystallography. The N-propargylated derivatives smoothly underwent intermolecular cyclizations to produce indolizine derivatives in good yields. We proposed a radical mechanism for the dimerization. Reaction of an allene product with butylated hydroxytoluene (BHT), a radical scavenger, did not give any dimerization product. This result supports the radical reaction.