NOVEL PYRAZOLE-CENTERED DERIVATIVES HAVING MONO/DI CHIRAL CENTERED GROUP AS ORGANOCATALYST FOR HENRY REACTION

Cetin A., Bildirici İ., Gümüş S.

MACEDONIAN JOURNAL OF CHEMISTRY AND CHEMICAL ENGINEERING, vol.39, no.1, pp.17-30, 2020 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 39 Issue: 1
  • Publication Date: 2020
  • Doi Number: 10.20450/mjcce.2020.1954
  • Journal Name: MACEDONIAN JOURNAL OF CHEMISTRY AND CHEMICAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier
  • Page Numbers: pp.17-30
  • Keywords: asymmetric catalyst, chirality, chiral amino alcohol, Lewis acid, pyrazole, ENANTIOSELECTIVE SYNTHESIS, EXCHANGE, LIGANDS, BEARING, MOIETY

Abstract

The chiral substituted pyrazole-3-carboxamides (4a-c), pyrazole-3-carboxylates (5a-c), pyrazole-3-thioureides (7a-c) and pyrazole-3,4-dicarboxamides (10a-c) were prepared via the pyrazolo-3-chlorocarbonyl 2, pyrazolo-3,4-dicarboxy methyl ester 3 with pyrazole-3-isothiocyanate 6 with different (R)-chiral amino alcohols. All of the synthesized chiral compounds binding a pyrazole skeleton were investigated as organocatalysts for asymmetric aldol reactions between nitromethane and p-nitrobenzaldehyde in the presence of CuCl. Enantiomeric excesses and the reaction yields were found to be appropriate values. Furthermore, the best organocatalyst applied in this study was identified after careful optimization of conditions. Lastly, all of the novel compounds were subjected to computational analysis at the B3LYP/6-31++G(d,p) level of theory to obtain information about their structural and electronic properties.