Enantioselective Alkylation of Amino Acid Derivatives Promoted by Cyclic Peptoids under Phase-Transfer Conditions

J Org Chem. 2016 Mar 18;81(6):2494-505. doi: 10.1021/acs.joc.6b00065. Epub 2016 Mar 8.

Abstract

The effects of substituents and cavity size on catalytic efficiency of proline-rich cyclopeptoids under phase-transfer conditions were studied. High affinity constants (Ka) for the sodium and potassium cations, comparable to those reported for crown ethers, were observed for an alternated N-benzylglycine/L-proline hexameric cyclopeptoid. This compound was found to catalyze the alkylation of N-(diphenylmethylene)glycine cumyl ester in values of enantioselectivities comparable with those reported for the Cinchona alkaloid ammonium salts derivatives (83-96% ee), and with lower catalyst loading (1-2.5% mol), in the presence of a broad range of benzyl, allyl and alkyl halides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Arginine / chemistry*
  • Benzene Derivatives / chemistry*
  • Cinchona Alkaloids / chemistry*
  • Glycine / analogs & derivatives*
  • Glycine / chemistry
  • Molecular Structure
  • Peptides, Cyclic / chemistry*
  • Proline / analogs & derivatives
  • Proline / chemistry*
  • Stereoisomerism

Substances

  • Benzene Derivatives
  • Cinchona Alkaloids
  • N-(diphenylmethylene)glycine cumyl ester
  • Peptides, Cyclic
  • Arginine
  • Proline
  • N-benzylglycine
  • Glycine