Dr. Miha Virant
Photography: Archive Krka, d. d., Novo mesto
Publish Date: 11.11.2020
Category: Researchers in focus , Our contribution to sustainable development goals
Sustainable development goals: 9 Industry, innovation and infrastructure, 12 Responsible consumption and production (Indicators)
Catalysts are molecules that allow more complex chemical reactions to take place or accelerate them. Today, catalysts are indispensable to industry, as more than 90% of the materials in everyday use are produced using at least one catalysed step. New, more efficient catalysts, developed in academic research, consequently lower the costs of industrial chemical processes, making products more accessible.
In his doctoral thesis, Dr Miha Virant from the University of Ljubljana’s Faculty of Chemistry and Chemical Technology focused on the development of new palladium catalysts. As part of a research group led by Prof. Janez Košmrlj (kosmrlj-group.com, @KosmrljGroup), Dr Virant studied different approaches to increasing the efficiency of palladium-based catalysts, which would significantly rationalise a number of important industrial processes. His work was recognised by the pharmaceutical company Krka, which awarded Dr Virant the Krka Grand Prize, an award that marks its 50th anniversary this year.
Dr Virant devoted much of his research to the development of new ligands (J. Org. Chem. 2019, 84, 14030), i.e. molecules in solution that surround a metal, thereby activating it to improve its functions, while also stabilising it so these functions are active for a longer period of time.
Research related to these ligands and their palladium compounds has provided important insights into the Sonogashira reaction. The latter is a fusion reaction in which two organic fragments are covalently coupled. This approach allows the synthesis of many complex molecules, indispensable in everyday life. Examples in the pharmaceutical industry include the synthesis of active substances such as Terbinafine (Sandoz), Ponatinib (Ariad Pharmaceuticals), Tazarotene (Allergan), and Eniluracil (GlaxoSmithKline). Dr Virant’s contribution to the combined experimental and theoretical study (Nat. Commun. 2018, 9, 4814) focused on the reaction mechanism of this process, which has been a mystery to scientists since its discovery. He and his colleagues have shown that, contrary to expectations, the Sonogashira reaction takes place with the participation of two, rather than one, independent palladium catalytic cycles. Understanding this reaction at the molecular level has exceptional potential, as it contributes to the ecological and economic sustainability of the chemical industry through a more rational use of precious metals, improved product efficiencies, and a decrease in waste generation. Preliminary results in this direction have been recently published by the research team (Org. Lett. 2020, 22, 4938).
The palladium complex with the ligand developed in the study (Chem. Commun. 2016, 52, 1571) has shown exceptional catalytic activity in the formation of imines, nitrogen organic compounds which are an important raw material in the production of various natural and bioactive compounds. The exceptional feature of the ligand is its versatility, as it not only stabilises and activates the metal centre, but enables the intramolecular proton transfer between reactive species in the catalytic cycle. The idea for such a catalyst was based on the enzyme-catalysed proton transfer reactions. The preliminary findings, published in a prominent international journal, (Org. Lett. 2020, 22, 2157), are the result of a close collaboration with the Physical Chemistry Laboratory at the Universidad Técnica Federico Santa María in Valparaíso, Chile, headed by Prof. Balazs Pinter, where Dr Virant conducted research during his doctoral studies. The significance of the study’s findings was also highlighted by the journal Organic Letters, which featured the article on its cover.