Octopus[5]arene\nfrom Pagoda[5]arene by Macrocycle-to-Macrocycle\nConversion

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