Bis- and tetracalix[4]arenes in the partial cone conformation: synthesis, structure and RCM reactions

Multifold ring closing metathesis reactions in the formation of resorcin[4]arene cavitands

The formation of the resorcin[4]arene cavitands by the ring closing metathesis (RCM) reaction depends, to a large extent, on the conformation and the substituents on the upper and lower rim of the perallylated resorcin[4]arenes.

Calix[4]arene daisychains

Generic calix[4]arenes became readily accessible in the late 70s. With their potential eight anchoring points, their utility for the production of sophisticated, highly functionalised macrocyclic molecules was rapidly recognised. While most studies in calixarene chemistry have focused on monocalixarene derivatives, there is now an increasing interest in developing multicalixarene compounds, especially those made of several linearly-arranged calix[4]arene units, the first examples of which were reported in 1989. This critical review will present the most important synthetic routes to such molecules together with an analysis of the properties that such cavity combinations may induce. In particular it will be shown that the nature of the links between the calixarene units plays a determinant role in the product properties and that singly-linked calixarenes can be exploited in varied applications, including those as efficient receptors of large molecules, as electrochemical and luminescent sensors in ion detection, or as new materials allowing capsule formation suitable for the storage of small guests (82 references).