Synthesis of 1-Azaspiro[4.5]deca-1,3-dienes from N-Propargylic beta-Enaminones in Basic Medium


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KARADENİZ E., ZORA M.

SYNTHESIS-STUTTGART, vol.51, no.10, pp.2157-2170, 2019 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 51 Issue: 10
  • Publication Date: 2019
  • Doi Number: 10.1055/s-0037-1611723
  • Journal Name: SYNTHESIS-STUTTGART
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.2157-2170
  • Keywords: pyrroles, 2H-pyrroles, N-propargylic beta-enaminones, spiro compounds, nucleophilic cyclization, ASYMMETRIC ALLYLIC DEAROMATIZATION, INTRAMOLECULAR CYCLIZATION, ENANTIOSELECTIVE SYNTHESIS, STEREOSELECTIVE-SYNTHESIS, CATALYZED CYCLIZATION, CONJUGATED POLYMERS, SELECTIVE SYNTHESIS, CASCADE SYNTHESIS, FACILE SYNTHESIS, PYRROLES

Abstract

A facile, efficient and unprecedented method for the synthesis of spiro-2H-pyrroles is reported. When reacted with 1-ethynylcyclohexylamine, a, ss-alkynic ketones produced cyclohexane-embedded Npropargylic ss-enaminones, which in the presence of cesium carbonate underwent nucleophilic cyclization to afford 1-azaspiro[ 4.5] deca-1,3diene derivatives in good to excellent yields. This cyclization was found to be general for a variety of cyclohexane-embedded N-propargylic ss enaminones and demonstrated good tolerance to a broad range of aliphatic, aromatic and heteroaromatic groups with electron-withdrawing and electron-donating substituents. The decoration of pyrrole compounds with a spiro framework may exhibit potential for the synthesis of molecules of pharmacological interest.