A 1,4-Diphenyl-1,2,3-Triazole-Based β-Turn Mimic Constructed by Click Chemistry

A series of 1,4-diphenyl-1,2,3-triazole-incorporated amide derivatives have been designed and prepared. Xray crystallographic and (1D and 2D) 1H NMR studies reveal that these compounds fold into stable U-shaped conformations driven by three-center intramolecular C-H center dot center dot center dot O hydrogen-bonding formed between the triazole C-5 H atom and the two ether O atoms. Such folded structures make this 1,4-diphenyl-1,2,3-triazole skeleton a good candidate to be used as beta-turn mimic. To prove this, the formation of a beta-hairpin structure induced by this beta-turn motif has been further demonstrated.