Catalytic asymmetric synthesis of 3-aminooxindoles: enantiofacial selectivity switch in bimetallic vs monometallic Schiff base catalysis

J Am Chem Soc. 2010 Feb 3;132(4):1255-7. doi: 10.1021/ja908906n.

Abstract

A highly enantioselective catalytic asymmetric access to 3-aminooxindoles with a tetrasubstituted carbon stereocenter is described. 1-2 mol % of homobimetallic (R)-Ni(2)-Schiff base 1 catalyzed the asymmetric amination of 3-substituted oxindoles with azodicarboxylates to give (R)-products in 99-89% yield and 99-87% ee. Reversal of enantiofacial selectivity was observed between bimetallic and monometallic Schiff base complexes, and monometallic (R)-Ni-Schiff base 2c gave (S)-products in 98-80% ee. Transformation of the products into an optically active oxindole with a spiro-beta-lactam unit and a known key intermediate for AG-041R synthesis is also described.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amination
  • Catalysis
  • Indoles / chemical synthesis
  • Indoles / chemistry*
  • Molecular Structure
  • Oxindoles
  • Schiff Bases / chemical synthesis
  • Schiff Bases / chemistry*
  • Stereoisomerism

Substances

  • AG-041R
  • Indoles
  • Oxindoles
  • Schiff Bases
  • 2-oxindole