Autoaccelerative diazo coupling with calix[4]arene: unusual co-operativity of the calixarene hydroxy groups

Abstract

Diazo coupling between calix[4]arene and p-nitrobenzenediazonium ion selectively afforded the tetrasubstituted calix[4]arene and almost no mono-, di-, and tri-substituted calix[4]arenes even in the presence of unchanged calix[4]arene: the unusual all-or-nothing substitution is attributed to the specific hydrogen-bonding effect among the calixarene OH groups.