Metallocyclodextrins: Combining Cavitands with Metal Centres

In the last decades, combining the properties of a transition-metal ion with those of a covalently linked, molecular cavity has attracted a great deal of attention. Numerous studies focused on the design and synthesis of systems exploiting the binding properties of a receptor moiety attached to an active metal site, with the aim of mimicking nature’s metal-containing catalysts: metalloenzymes. Other potential applications involve (1) the study of metal-promoted reactions occurring in a confined environment in order to find out whether this strategy leads to selective transformations, and (2) molecular recognition via supramolecular interactions in conjunction with photoor electrochemical applications. In this respect, cyclodextrins (CDs) and their chemically modified derivatives occupy a position of choice. Their rigid, conical structure, inherent chirality, as well as the presence of hydroxy groups that can be substituted in a regioselective manner, offer many possibilities in terms of cavitand (cavity-shaped ligand) design. So far, most studies have dealt with the smallest member of the family, namely a-CD, because of the ease with which it can be functionalised, b-CD derivatives remaining largely unexplored, even if their bigger inner space seems more appropriate for taking full advantage of the cavity. The present thesis is mainly concerned with the preparation of new introverted phosphanes (WIDEPHOS and L, Figure 1) derived from multifunctionalised methylated b-CDs and the study of their coordination and catalytic properties. The last part of the manuscript focuses on the use of