Development of convergent synthetic method for saccharide-linked ethynylpyridine foldamers by Huisgen reaction

Based on ‘click chemistry’, the new convergent synthesis to a variety of saccharide-linked 2,6-pyridylene ethynylene ‘ethynylpyridine’ foldamers was developed. Ethynylpyridine 6-, 9-, and 12-meric blocks were linked with 1,7-octadiyne linker block by Sonogashira reaction, and joined with azido group-introduced glucoside, galactoside, and mannoside templates by Huisgen reaction. The resulting saccharide-linked ethynylpyridine foldamers exhibited typical circular dichroism to indicate the formation of a helical structure by intramolecular hydrogen bonds.