Asymmetric conjugate reductions with samarium diiodide: asymmetric synthesis of (2S,3R)- and (2S,3S)-[2-2H,3-2H]-leucine-(S)-phenylalanine dipeptides and (2S,3R)-[2-(2)H,3-2H]-phenylalanine methyl ester

Org Biomol Chem. 2005 Apr 21;3(8):1435-47. doi: 10.1039/b500566c. Epub 2005 Mar 17.

Abstract

The highly diastereoselective samarium diiodide and D(2)O-promoted conjugate reduction of homochiral (E)- and (Z)-benzylidene and isobutylidene diketopiperazines (E)-5,7 and (Z)-6,8 has been demonstrated. This methodology allows the asymmetric synthesis of methyl (2S,3R)-dideuteriophenylalanine 27 in > or = 95% de and >98% ee, and (2S,3R)- or (2S,3S)-dideuterioleucine-(S)-phenylalanine dipeptides 37 and 38 in moderate de, 66% and 74% respectively. A mechanism is proposed to account for this process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallography, X-Ray
  • Dipeptides / chemical synthesis*
  • Dipeptides / chemistry
  • Iodides / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Oxidation-Reduction
  • Phenylalanine / analogs & derivatives*
  • Phenylalanine / chemical synthesis
  • Phenylalanine / chemistry
  • Samarium / chemistry*
  • Stereoisomerism

Substances

  • Dipeptides
  • Iodides
  • leucyl-phenylalanine
  • phenylalanine methyl ester
  • Samarium
  • Phenylalanine
  • samarium diiodide