Copper(I)-Catalyzed Asymmetric Synthesis of Unnatural α-Amino Acid Derivatives and Related Peptides Containing γ-(aza)Aryls

J Org Chem. 2022 Jan 7;87(1):399-405. doi: 10.1021/acs.joc.1c02426. Epub 2021 Dec 15.

Abstract

Chiral α-amino acids are indispensable compounds in organic chemistry, biochemistry, and medicinal chemistry. Herein, by means of copper(I)-catalyzed asymmetric conjugate addition of derivatives of glycine, serine, cysteine, and β-amino-alanine to electron-deficient vinyl(aza)arenes, an array of novel unnatural chiral α-amino acid derivatives bearing a γ-(aza)aryl is prepared in moderate to high yields with high enantioselectivity. Various azaarenes, such as pyrimidine, 1,3,5-triazine, pyridine, pyridine-N-oxide, quinoline, quinoxaline, purine, benzo[d]imidazole, benzothiazole, and 1,2,4-oxadiazole, are well tolerated. Moreover, the electrophiles are nicely extended to (Z)/(E) mixtures of electron-deficient butadienylpyridine and benzene, which are transformed to the corresponding chiral α-amino acid derivatives in high (E)/(Z) ratio and high enantioselectivity. More importantly, the present methodology is successfully applied in the catalytic asymmetric functionalization of Schiff bases derived from peptides, which finally afforded a new chiral tripeptide bearing two electron-deficient azaaryls and one electron-deficient aryl in high total yield with high diastereo- and excellent enantioselectivities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids*
  • Catalysis
  • Copper*
  • Peptides
  • Stereoisomerism

Substances

  • Amino Acids
  • Peptides
  • Copper