OMC Scientific day
3 guest speakers as part of Zilong LI's thesis defense
Mercoledì 20 novembre 2024, 10:30Passato
Organometallics: Materials and Catalysis team
10h00 - Pr Christophe Thomas
UMR CNRS 8247 - Chimie ParisTech - Institut de Recherche de Chimie Paris (France)
- One-Pot Catalysis: A Privileged Approach for Sustainable Polymers
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10h35 - Dr Erwan Le Grognec
UMR CNRS 6230 - Chimie et Interdisciplinarités, Synthèse, Analyse, Modélisation - Université de Nantes (France)
- Solid-supported Chemistry and Continuous Flow: efficient tools in Organic Chemistry
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11h10 - Pr Blanca Martin Vaca
UMR CNRS 5069 - Laboratoire Hétérochimie Fondamentale et Appliquée - Université de Toulouse 3, Paul Sabatier (France)
- Two stories on the importance of structural fine-tuning: Metal-ligand cooperative Catalysis with Pd and New monomers for Ring-Opening Polymerization
Abstract:
This PhD demonstrated the potential of functionalized ligands to significantly enhance the performances of ruthenium and iridium catalysts in a variety of reactions. The research aligned with the principles of sustainable chemistry achieving green processes through additive-free catalytic reactions. Formic acid was used as a liquid organic hydrogen carrier (LOHC) to release hydrogen and conduct selective reduction of ketones and furfural, a bio-based chemical. Previous studies demonstrated that the sulfate ligand in iridium catalysts played the role of base during formic acid dehydrogenation. Building on this finding, the ligand design strategy was expanded, focusing on bifunctional catalysts to enhance metal-ligand cooperation. Several new ruthenium and iridium catalysts have been synthesized and compared to previously reported catalysts across formic acid dehydrogenation and reduction reactions, revealing that functionalized ligands contributed significantly to improved catalytic performance.
In the case of ruthenium catalysts, a new scorpion-complex was synthesized, which successfully facilitated base-free transfer hydrogenation of unsaturated C=O bonds. The catalyst also displayed strong tolerance to steric hindrance and various functional groups, as well as high chemical selectivity in reduction reactions. For iridium catalyst incorporating both electron-donating and carboxylate groups, a significantly enhanced catalytic activity was obtained for formic acid dehydrogenation when compared to previously studied catalysts. This catalyst demonstrated more than double the activity of the earlier catalyst under the same reaction conditions. Additionally, it was able to dehydrogenate neat formic acid, achieving the highest reported TOF without additives. The research also explored the catalytic reduction of furfural into furfuryl alcohol. Using a bipyridine-based iridium catalyst, excellent results were achieved under mild conditions.
Contact: Cédric Fischmeister (3 59 98) - cedric.fischmeister@univ-rennes.fr
