Dottorato in SCIENZE CHIMICHE

Titolo della tesi: A supramolecular approach to hydrocarbon functionalization

Transition metal-based catalysis of C-H oxidation is quickly becoming a viable route for hydrocarbon functionalization. The possibilities for Organic Synthesis are exciting: new transformations are now available to the Chemist to design more elegant syntheses and to generate huge libraries of molecules through late-stage functionalization. However, that of selectivity is still a largely unsolved problem: for particular combinations of substrates and catalytic systems, steric and electronic effects can direct the oxidation on few specific sites but, in most cases, mixtures of products are formed. Supramolecular chemistry studies the interactions between distinct molecules. This branch of chemistry has found application in the development of catalysts that can recognize their substrate and orient it in such a way as to enhance the reactivity and selectivity of the catalytic system. The supramolecular approach can be defined as biomimetic; indeed, enzymes employ supramolecular interactions with their substrates to achieve their paradigmatic selectivity. This thesis explores the application of supramolecular recognition to hydrocarbon functionalization: a successful supramolecular system for C-H oxidation is studied in detail, then an attempt at designing a new imine-based supramolecular catalyst is made. Finally, a UV-Vis/XAS coupled technique is developed and the analysis of time-resolved XAS data is used for the first time to follow the reactions between a non-heme iron-oxo complex and various substrates to determine their rate constants.