Asymmetric synthesis of aryl-substituted pyrrolidines by using CFAM ligand–AgOAc chiral system via 1,3-dipolar cycloaddition reaction

Beksultanova N., DOĞAN Ö.

Chirality, vol.35, no.7, pp.435-448, 2023 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 35 Issue: 7
  • Publication Date: 2023
  • Doi Number: 10.1002/chir.23557
  • Journal Name: Chirality
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Applied Science & Technology Source, BIOSIS, Biotechnology Research Abstracts, Chemical Abstracts Core, Chimica, EMBASE, MEDLINE
  • Page Numbers: pp.435-448
  • Keywords: 1, 3-DC reaction, chiral metal catalyst, chiral pyrrolidines, NON-BIARYL ATROPISOMERS, AZOMETHINE YLIDES, CATALYSTS
  • Middle East Technical University Affiliated: Yes

Abstract

We have prepared a ligand library based on a ferrocenyl aziridinyl methanol core unit (simply called FAM) having a phenyl group, a cyclohexyl group, and a naphthyl group to be used in 1,3-dipolar cycloaddition (1,3-DC) reactions for the synthesis of chiral pyrrolidines. These chiral ligands were used with AgOAc in 1,3-DC reactions taking place between the aryl-substituted azomethine ylides and N-methylmaleimide as the dipolarophile. In each case, the expected aryl-substituted pyrrolidines were obtained in good to excellent yields with acceptable enantioselectivities favoring only the endo product. The chiral catalyst system CFAM4–AgOAc was also used in 1,3-DC reaction with different dipolarophiles such as dimethyl maleate, tert-butyl acrylate, methyl acrylate, trans-chalcone, and vinyl sulfone. In each case, the cycloadducts were obtained in acceptable yields albeit with low ee. Fortunately, it was possible to increase the ee up to >99% upon crystallization.