Hydrogen-bonding interactions drive oligosquaramides of different lengths to fold into hairpin-like structures both in nonprotic and protic solvents. These compounds are useful preorganized precursors in macrocyclization reactions.
Efficient Macrocyclisation of Preorganized Palindromic Oligosquaramides
Angew. Chem. Int. Ed. 2006, 45, 6844-6848.