Asymmetric organocatalytic direct Mannich reaction of acetylacetone and isatin derived ketimines: Low catalyst loading in chiral cinchona-squaramides


İŞİBOL D., Karahan S. , TANYELİ C.

TETRAHEDRON LETTERS, vol.59, no.6, pp.541-545, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 59 Issue: 6
  • Publication Date: 2018
  • Doi Number: 10.1016/j.tetlet.2017.12.081
  • Title of Journal : TETRAHEDRON LETTERS
  • Page Numbers: pp.541-545
  • Keywords: Asymmetric organocatalysis, Mannich reaction, 3-Amino-2-oxindole, Isatin ketimine, Bifunctional squaramide, ENANTIOSELECTIVE MICHAEL ADDITION, PICTET-SPENGLER REACTIONS, AZA-HENRY REACTION, CONJUGATE ADDITION, ALPHA-AMINATION, CHEMICAL SPACE, CONTIGUOUS STEREOCENTERS, RECEPTOR ANTAGONIST, DERIVATIVES, 3-AMINOOXINDOLES

Abstract

A highly enantioselective synthesis of 3-amino-2-oxindoles by direct Mannich reaction between acetylacetone and N-carbamoyl isatin ketimine has been described herein. Corresponding chiral adducts were obtained in high yields (up to 98%) and with excellent enantioselectivities (up to >99% ee) by very low (1 mol%) catalyst loading of 2-adamantyl substituted bifunctional cinchona-squaramide. (C) 2017 Elsevier Ltd. All rights reserved.