Vancomycin-Iridium (III) Interaction: An Unexplored Route for Enantioselective Imine Reduction

Molecules. 2019 Jul 30;24(15):2771. doi: 10.3390/molecules24152771.

Abstract

The chiral structure of antibiotic vancomycin (Van) was exploited as an innovative coordination sphere for the preparation of an IrCp* based hybrid catalysts. We found that Van is able to coordinate iridium (Ir(III)) and the complexation was demonstrated by several analytical techniques such as MALDI-TOF, UV, Circular dichroism (CD), Raman IR, and NMR. The hybrid system so obtained was employed in the Asymmetric Transfer Hydrogenation (ATH) of cyclic imines allowing to obtain a valuable 61% e.e. (R) in the asymmetric reduction of quinaldine 2. The catalytic system exhibited a saturation kinetics with a calculated efficiency of Kcat/KM = 0.688 h-1mM-1.

Keywords: asymmetric hydrogen transfer; glycopeptides; hybrid catalyst.

MeSH terms

  • Anti-Bacterial Agents / chemistry*
  • Catalysis
  • Coordination Complexes / chemistry*
  • Hydrogenation
  • Imines / chemistry*
  • Iridium / chemistry*
  • Kinetics
  • Oxidation-Reduction
  • Quinaldines / chemistry
  • Stereoisomerism
  • Vancomycin / chemistry*

Substances

  • Anti-Bacterial Agents
  • Coordination Complexes
  • Imines
  • Quinaldines
  • Iridium
  • Vancomycin
  • 2-methylquinoline