Catalytic asymmetric synthesis of protected tryptophan regioisomers

J Org Chem. 2002 Aug 23;67(17):6256-9. doi: 10.1021/jo025964i.

Abstract

Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation-pi interaction). In an effort to expand the toolbox of Trp-like amino acids, in this note we report catalytic asymmetric syntheses of Trp regioisomers 2a-e, where the alanine unit is attached not to C-3 of indole but to C-2, C-4, C-5, C-6, or C-7. Excellent asymmetric induction is obtained in each case (generally >97% ee). Ab initio calculations suggest that the indole nuclei of 2a-e will bind Na(+) with the same affinity as that of Trp.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cations / chemistry
  • Chemistry, Organic / methods*
  • Hydrogenation
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Molecular Conformation
  • Molecular Structure
  • Peptides / chemistry*
  • Protein Binding
  • Stereoisomerism
  • Tryptophan* / analogs & derivatives
  • Tryptophan* / chemical synthesis
  • Tryptophan* / chemistry

Substances

  • Cations
  • Indoles
  • Peptides
  • Tryptophan