Aromatic Oligoamide Foldamers

Abstract Aromatic oligoamide foldamers possess a high potential for mimicking the secondary structures of biopolymers. These oligomers are efficiently designed, easy to synthesize, and allow one to reach a wide range of stable folded states. The aryl−amide bond rotation can be restricted through specific attractive and repulsive interactions between the amide and the other functional groups at the ortho position on the aryl moiety. The overall conformation of an oligomer results from the simple linear combination of the local conformational preferences at each amide bond. Thus, the curvature of the oligomeric strand may be tuned from strictly linear to highly bent, giving rise to helices of controllable diameter and extended linear conformations. Conformational rearrangements such as helical−linear strand transitions may be induced upon changing the local conformational preference of aryl−amide bonds. These oligomers also aggregate in various ways, such as stacks of discs, face‐to‐face hydrogen‐bonded linear dimers, or entwined double helices. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)