Synthesis and binding studies of multiple calix[4]arenes

As novel host molecules, various double and quadruple calix[4]arenes have been synthesized by using quadruple cycloadditive macrocyclization, Schiff-base formation, and acylation. The interesting features of ‘head-to-head’ type multiple calix[4]arenes, such as the conformational aspects and cooperative binding, have been studied.