Enantioselective sulfa-Michael addition reaction of methyl thioglycolate to chalcones derivatives with sterically encumbered quinine squaramide organocatalyst


HASILCIOĞULLARI D., TANYELİ C.

TETRAHEDRON LETTERS, vol.59, no.14, pp.1414-1416, 2018 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 59 Issue: 14
  • Publication Date: 2018
  • Doi Number: 10.1016/j.tetlet.2018.02.068
  • Journal Name: TETRAHEDRON LETTERS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1414-1416
  • Keywords: Asymmetric catalysis, Asymmetric synthesis, Organocatalysis, Conjugate addition, Sulfa-Michael addition, CHIRAL PRIMARY AMINE, CONJUGATE ADDITION, BIFUNCTIONAL ORGANOCATALYSTS, ASYMMETRIC ORGANOCATALYSIS, CATALYST, KETONES, NITROALKENES, ACCESS, THIOLS

Abstract

Asymmetric organocatalytic sulfa-Michael reactions give access to enantiomerically enriched sulfur containing adducts that can be used as valuable chiral building blocks. A variety of chalcone derivatives were allowed to react with methyl thioglycolate under optimized conditions, in the presence of a bifunctional quinine derived sterically encumbered squaramide organocatalyst, giving rise to excellent stereoselectivities, up to 99% ee. The designed catalyst system proved to be efficient even at gram scale and under milder reaction conditions. (C) 2018 Elsevier Ltd. All rights reserved.