Synthesis of the Bi-functionalized Pillar[5]arene

The method for the synthesis of bi-functionalized pillar[5]arenes with amino and ester groups or amino and carboxylic group has been developed. The conformation of the functional group of the pillar[5]arene was investigated by using H-1 NMR and X-Ray experiments. The intramolecular hydrogen bonding induces the side-chain of the pillar[5]arene to introvert. And thus, the amino group points to the inside cavity of the pillar[5]arene backbone. The position of the amino group is adjustable by using alkyl chains with different length.