Asymmetric synthesis of chiral primary amines by transfer hydrogenation of N-(tert-butanesulfinyl)ketimines

J Org Chem. 2010 Aug 6;75(15):5265-70. doi: 10.1021/jo101057s.

Abstract

The diastereoselective reduction of (R)-N-(tert-butanesulfinyl)ketimines by a ruthenium-catalyzed asymmetric transfer hydrogenation process in isopropyl alcohol, followed by desulfinylation of the nitrogen atom, is an excellent method to prepare highly enantiomerically enriched alpha-branched primary amines (up to >99% ee) in short reaction times (1-4 h). (1S,2R)-1-Amino-2-indanol has been shown to be a very efficient ligand to perform this transformation. Ketimines bearing either an aryl or a heteroaryl group and an alkyl group as substituents of the iminic carbon atom are very good substrates for this process. The reduction of a dialkyl ketimine could also be achieved, affording the expected amine with moderate optical purity (69% ee). Some amines which are precursors of very interesting biologically and pharmacologically active compounds have been prepared in excellent yields and enantiomeric excesses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amines / chemical synthesis*
  • Amines / chemistry
  • Hydrogen / chemistry*
  • Imines / chemistry*
  • Magnetic Resonance Spectroscopy
  • Nitriles / chemistry*
  • Spectrophotometry, Infrared
  • Stereoisomerism

Substances

  • Amines
  • Imines
  • Nitriles
  • ketimine
  • Hydrogen