The development of alternative greener synthetic methods to transform renewable feedstocks into elaborated chemical structures is a prerequisite for a future sustainable society. In this regard, this project entails the use of visible light or redox potential as driving force for the synthesis of fuels and high-value chemicals.
The project merges (photo-)redox catalysis with 1st row transition metal complexes catalysis to develop greener and selective catalytic reduction processes for organic substrates, water and CO2.
The ground-breaking features of this project are:
A) Study of advanced strategies for the reduction of protons to H2 and CO2 to CO with molecular complexes. During the last years we have developed well-defined coordination complexes with aminopyridine ligands, which have been proven to be very active catalysts for the photo- and electro-catalytic reduction of protons to H2 and CO2 reduction. Since these complexes are excellent modular and tuneable platforms we will study and evaluate their effect by introducing pendant bases, unusual non-innocent ligands and Lewis acids and bases in the ligand framework in catalysis.
B) Development of new light- or electro-driven regio- and/or enantioselective catalytic reductions using the same family of well-defined coordination complexes with aminopyridine ligands, initially developed for water reduction. Steric, electronic and supramolecular interactions (pi-stacking, apolar cavities and chiral pockets) will be studied for a proper control of the selectivity in i) the reduction of C=E and C=C bonds and ii) in the C-C inter- and intramolecular reductive homo- or heterocouplings.
C) Fundamental understanding of the light-driven cobalt catalysed reductions characterizing intermediates that are involved in the reactivity, by kinetics, labelling studies and by performing computational modelling of the reaction mechanisms. The basic understanding of the operative mechanisms will expedite a new methodology for electrophile-electrophile umpolung couplings.
As a proof of concept, our previous developed cobalt catalysts based on aminopyridine ligands, have shown to be highly active as catalysts i) for the reduction of water to hydrogen and ii) for the light-driven reduction of ketones, aldehydes and olefins, using water as the source of hydrogen atoms.