Stabilization of Chiral Helices for Saccharide-Linked Ethynylpyridine Oligomers Possessing a Conformationally Well-Defined Linkage

Tetrameric and octameric 2,6‐pyridylene ethynylene oligomers linked to a β‐D‐glucopyranoside template through an o‐phenylene linker were prepared and studied for their higher‐order structure. These oligomers formed chiral helical structures through intramolecular hydrogen bonding between the ethynylpyridine moiety and the glucoside template. The rigidity of the o‐phenylene linker stabilizes the helical structure to improve its CD activity and resistance against protic surroundings. Furthermore, the helical stabilization was enhanced by the addition of Cu(OTf)2 and Zn(NO3)2 salts. Tetrameric and octameric 2,6‐pyridylene ethynylene oligomers joined to a β‐D‐glucopyranoside by a o‐phenylene linker were prepared and their higher‐order structure studied. The chiral helical structures formed by intramolecular H‐bonding and linker stabilization improve CD activity and resistance to protic surroundings. Stabilization was enhanced with the addition of Cu(OTf)2 and Zn(NO3)2 salts.