Sara Ranjbar, PhD student under the supervision of Prof. Miquel A. Pericàs (ICIQ), Oliver Reiser (Universität Regensburg) and Carles Rodríguez-Escrich (ICIQ), has defended her PhD Thesis entitled
“Magnetic Nanoparticles as a Versatile Platform for Catalytic Applications”‘ (assigned to the Organic and Analytical Chemistry Department of the Universitat Rovira i Virgili) publicly on October 25th at the ICIQ Auditorium.
The members of the evaluation committee were: Prof. Montserrat Gómez (Université Paul Sabatier, Toulouse), Prof. Olga García-Mancheño (Universität Regensburg) and Prof. Arjan Kleij (ICIQ).
This thesis focuses on the application of magnetic nanoparticles (MNPs) in different catalytic reactions. In this research the main goal is to develop different catalysts based on MNPs and study the advantages and disadvantages of these catalytic materials.
In the first part of the research, two new hybrid materials based on carrageenan and MNPs were developed and tested in the Michael addition of aldehydes to nitroalkenes. The first one, a combination of carrageenan and MNPs, showed good results in this reaction while the individual components were inactive. The second catalyst, which included an analogue of the Jørgensen-Hayashi catalyst also showed good activity and excellent enantioselectivity.
In the second project, an analogue of the second generation MacMillan catalyst was immobilized onto Fe3O4 NPs and polystyrene. The resulting catalysts were applied to the asymmetric Friedel–Crafts alkylation of indoles with α,β-unsaturated aldehydes. In this study, the polystyrene-based catalyst showed higher stability and provided better stereoselectivity.
In the last project, another kind of hybrid material was synthesized based on microporous organic polymers (MOPs) encapsulated with Pd nanoparticle and Co/C nanobeads. To build up the polymer, different substrates such as toluene, aniline and phenol were used. After synthesising Pd nanoparticle inside of the pores of polymer, these catalysts were applied to the hydrogenation and Suzuki cross-coupling reactions. Despite moderate to good yields that were obtained, these catalysts suffer from leaching of Pd, so further research for optimizing this catalyst system is required.