Chiral Helical Aromatic Foldamers: Construction Strategies and Applications
The tertiary spatial structure of biological macromolecules determines their physiological functions. In the formation of the tertiary structure, the secondary structure serves as the assembly foundation, and interactions between secondary structures play a critical role in driving and stabilizing the tertiary architecture. Synthetic foldamers, characterized by their modifiability and structural diversity, can adopt various helical conformations, enabling them to mimic natural protein secondary structures such as the α-helix, while also providing chemical models for studying interactions between secondary structures. This review outlines recent advances in aromatic foldamers and supramolecular helical assemblies formed by helical polymers, with particular attention to unique chiral phenomena observed during the formation of helical secondary structures. It provides a detailed summary of their applications in molecular recognition, ion channels, and circularly polarized luminescence, among others, and discusses future challenges facing aromatic foldamers. The review emphasizes the hierarchical nature of chirality—from primary atomic asymmetry to quaternary higher-order structures—and highlights the importance of understanding non-covalent interactions between helical secondary structures for regulating chiral assembly. Key strategies for constructing chiral helical aromatic foldamers include the use of chiral side chains, terminal groups, and solvent effects, as well as the sergeants-and-soldiers effect and majority-rules principle for chirality amplification. The applications of these foldamers in asymmetric catalysis, chiroptical materials, and biomimetic ion transport are also discussed, underscoring their potential in advanced functional materials.