Calix[4]arenes and resorcinarenes bridged at the wider rim

Abstract

Calixarenes and resorcinarenes have been bridged at the wider rim with a variety of linking groups for a variety of applications. This chapter will outline some of the strategies used and provide a flavour of the range of linking groups investigated. Bridging calixarenes with four equivalent rings usually results in a mixture of predominantly mono- and di-proximally bridged derivatives. For the synthesis of distally bridged calixarenes, a selectively difunctionalised precursor is usually employed. Commonly used precursors are calixarenes functionalised with hydroxymethyl, halomethyl, formyl, amino or carboxy groups. Linking groups have included polyethers, thioethers, esters, amines, amides, acetals, siloxanes and hydrocarbons.