Continuous Flow Catalysis for the Valorization of Carbon Dioxide

Identifier:  TDX:4198

Handle: https://hdl.handle.net/20.500.11797/TDX4198

Authors:  Zanda, Nicola

Abstract:
The use of carbon dioxide as a sustainable alternative to more dangerous reagents is a topic of high interest in contemporary organic chemistry. Its conversion by a combination of heterogeneous organocatalytic means and Flow chemistry can further improve the sustainability of the processes. The objective of this doctoral thesis was to design a combination of setup and supported organocatalysts (metal and halide free) to convert CO2 into heterocyclic and small molecules of commercial and pharmaceutical interest. In the first chapter a set of catalyst was designed and applied to the synthesis of glycerol carbonate. The best catalyst was used to design a flow setup and glycerol carbonate was synthetized with high yield over two days of operation. Further optimization of the process lead to a more adaptable setup and to the selective synthesis of 2-substituted oxazolidinones. Finally, the formylation of various amines was explored. Various silanes and organocatalysts were screened to achieve a selective transformation under Batch and Continuous Flow Conditions. The experimental results from this dissertation portray the effectiveness of heterogeneous, metal- and halide-free organocatalysts in the conversion of carbon dioxide in continuous flow. The extent of the work will likely arise interest in the development of more sustainable alternative to the current state-of-art catalysts for future continuous flow scale up of these reactions.