Multipoint Molecular Recognition of Amino Acids and Biogenic Amines by Ureidocalix[5]arene Receptors

Abstract

[reaction: see text] p-tert-Butylcalix[5]arenes in a fixed cone conformation, endowed with a urea functionality at the upper rim, behave as remarkably efficient abiotic receptors of omega-amino acids and biogenic amines, which are bound with one end of the chain within the pi-basic cavity (primary recognition site) and the other grasped by the secondary hydrogen bonding donor/acceptor binding site.