α,β-Unsaturated γ-Peptide Foldamers

Graphical Abstract

Foldamer science has far highlighted the use of pre-organized scaffolds to impose a strict control of the backbone torsional angles and stabilize discrete secondary structures. In this context, oligomers with α,β-unsaturated γ-amino acids have attracted attention because of their conformational stability in both organic solvent and aqueous medium. This Review provides a comprehensive overview of α,β-unsaturated γ-peptide foldamers.

Abstract

Despite their concomitant emergence in the 1990s, γ-peptide foldamers have not developed as fast as β-peptide foldamers and to date, only a few γ-oligomer structures have been reported, and with sparse applications. Among these examples, sequences containing α,β-unsaturated γ-amino acids have recently drawn attention since the Z/E configurations of the double bond provide opposite planar restrictions leading to divergent conformational behaviors, from helix to extended structures. In this Review, we give a comprehensive overview of the developments of γ-peptide foldamers containing α,β-unsaturated γ-amino acids with examples of applications for health and catalysis, as well as materials science.