Condensation Approach to Aliphatic Oligourea Foldamers: Helices with <i>N</i>‐(Pyrrolidin‐2‐ylmethyl)ureido Junctions

Abstract

Caught in a fold: A simple and efficient coupling strategy to make aliphatic oligourea foldamers is reported. Crystal structures show that the pyrrolidine units (red; see picture) do not impair the 2.5-helical folding of the oligoureas. This modular strategy enables assembly of long helical segments containing non-adjacent pyrrolidine units as exemplified by the synthesis of a helix that is approximately 40 Å long.