Octopus[5]arene from Pagoda[5]arene by Macrocycle-to-Macrocycle Conversion

Macrocycle-to-macrocycle conversion is an effective strategy to construct new macrocyclic arenes with specific structures. Herein, a new class of chiral macrocyclic arene, namely, octopus[5]arenes (Oc5s), cannot be synthesized by the direct approach from the corresponding chiral monomers but can be successfully achieved by a macrocycle-to-macrocycle conversion strategy utilizing racemic pagoda[5]arenes as the starting materials. It was found that enantiomeric Oc5s showed fixed conformations and stable chiral structures and exhibited significant chiral recognition toward chiral diamines.