Peptoids are a class of synthetic foldamers that are being developed as potential therapeutics, biomaterials, and organocatalysts. In particular, peptoids represent an attractive platform for pharmaceutical applications, as they are highly resistant to protease degradation. However, given their tertiary amide backbone, peptoids lack the capacity to form hydrogen bonds so their secondary structures are dominated by relatively weak interactions. Considerable efforts have been made to try and understand the relationships between a peptoid primary sequence and its folded structure. Cis/trans isomerization of the tertiary amide bond is the major cause of conformational heterogeneity in peptoid oligomers. We have sought to explore the application of fluorine as a tool to modulate the conformational preferences of peptoid monomers. Here our recent work^1,2 on the design and development of new fluorinated peptoid monomers that have the ability to induce a cis isomer preference and stabilise helical structures in peptoid oligomers will be presented. The potential applications of these new fluorinated peptoid oligomers in the design of novel anti-infective agents will also be discussed.

1. Gimenez D., Aguilar, J.A., Bromley, E.H.C., Cobb S.L. “Stabilising Peptoid Helices Using Non-Chiral Fluoroalkyl Monomers” Angew. Chem. Int. Ed. 2018, 57, 10549 –10553
2. Gimenez D, Zhou G., Hurley, M.F.D., Aguilar J.A., Voelz V.A., Cobb S.L “Fluorinated Aromatic Monomers as Building Blocks To Control α-Peptoid Conformation and Structure” J. Am. Chem. Soc. 2019, 141, 8, 3430-3434