Final Report Summary - CO2RECYCLING (A Diagonal Approach to CO2 Recycling to Fine Chemicals)
While 95% of chemical commodities rely on non-renewable resources namely hydrocarbons, the re-use of atmospheric CO2 becomes urgent and its conversion to chemicals represents an opportunity to achieve an improved sustainability of the chemical industry, in the long run. New methods for the chemical recycling of carbon dioxide are needed, to use CO2 as a C1 building block for the production of organic chemicals. Yet, as a waste, CO2 is thermodynamically and kinetically difficult to transform and only three chemical processes recycling CO2 have been industrialized to date. To expand the scope of fine chemicals available from CO2, the idea behind the CO2Recycling project is to design novel catalytic transformations where CO2 is reacted, in a single step, with a functionalizing reagent and a reductant that can be independently modified, to produce a large spectrum of molecules. This approach has been explored through the development of novel molecular catalysts able to activate CO2 and/or suitable reductants (including hydrosilanes, hydroboranes, and formic acid). It has led to the discovery of new catalytic transformations where CO2 can be converted to methylamines for the first time. The formation of esters and poly-esters has been demonstrated from the reaction between CO2 and organosilanes. The results have also increased our understanding of CO2 activation and transformation and provided invaluable insights into the basic modes of action of organocatalysts in reduction chemistry, for example the catalytic role of Frustrated Lewis Pairs in the activation and conversion of CO2. Beyond CO2 utilization, the mechanistic studies have led to the development of new transformations for the preparation of sulfones from SO2 and the isolation of aromatic products from wood lignin. They will serve the scientific community involved in the field of organocatalysis, green chemistry and energy storage.