Bifunctional Thiourea-Ammonium Salt Catalysts Derived from Cinchona Alkaloids: Cooperative Phase-Transfer Catalysts in the Enantioselective Aza-Henry Reaction of Ketimines

J Org Chem. 2018 Feb 2;83(3):1486-1492. doi: 10.1021/acs.joc.7b03078. Epub 2018 Jan 5.

Abstract

An efficient enantioselective aza-Henry reaction of aryl α-ketoester-derived ketimines has been realized by using bifunctional thiourea-ammonium salt phase-transfer catalysts, which were derived from quinine. A variety of aryl α-ketoester-derived N-Ts ketimines were investigated, and the corresponding products were obtained in high to excellent yields (up to 99%) with good to high enantioselectivities (up to >99% ee).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Compounds / chemistry*
  • Catalysis
  • Cinchona Alkaloids / chemistry*
  • Imines / chemistry*
  • Molecular Structure
  • Nitriles / chemistry*
  • Salts / chemistry
  • Stereoisomerism
  • Thiourea / chemistry*

Substances

  • Ammonium Compounds
  • Cinchona Alkaloids
  • Imines
  • Nitriles
  • Salts
  • ketimine
  • Thiourea