2026-04-17T04:22:15Zhttps://recercat.cat/oai/request

oai:recercat.cat:2072/4733672024-11-04T07:14:04Zcom_2072_98col_2072_378192

Dissimilar catalytic behavior of molecular or colloidal palladium systems with a new NHC ligand Gómez-Villarraga, Fernando De Tovar Villanueva, Jonathan Guerrero, Miguel Nolis Fañanas, Pau Parella Coll, Teodor Lecante, Pierre Romero Fernández, Nuria Escriche Martínez, Lluís Bofill Arasa, Roger Ros i Badosa, Josep Sala Román, Xavier Philippot, Karine García-Antón, Jordi In this work, we describe the synthesis of a new N-heterocyclic carbene (NHC) ligand, derived from a hybrid pyrazole-imidazolium scaffold, namely 1-[2-(3,5-dimethylpyrazol-1-yl)ethyl]-3-((S)-1-phenylethyl)-3H-imidazol-2-ylidene (L). This ligand has been used as a stabilizer for the organometallic synthesis of palladium(0) nanoparticles (Pd NPs). L presents a better stabilizing effect than its pre-carbenic HLCl counterpart, allowing the formation of isolated Pd NPs while HLCl yields aggregated ones. Additionally, molecular Pd(ii) coordination compounds of L and HLCl were synthesized and characterized to better understand the coordination modes of these ligands. Both molecular and colloidal Pd systems have been further tested in catalytic C-C coupling processes. Three different types of reactions have been observed depending on the catalytic system: (i) the Suzuki-Miyaura reaction takes place with Pd molecular complexes; (ii) a secondary reaction, the dehalogenation of the substrate, is always detected and (iii) the C-C homocoupling between two molecules of bromoarenes is observed with colloidal catalysts. 2024-11-04T07:14:04Z 2024-11-04T07:14:04Z 2024-11-04T07:14:04Z 2017 Article http://hdl.handle.net/2072/473367 Ministerio de Economía y Competitividad CTQ2015-64261-R Ministerio de Economía y Competitividad CTQ2015-64436-P Dalton transactions ; Vol. 46, Issue 35 (August 2017), p. 11768-11778 open access Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. https://creativecommons.org/licenses/by-nc/4.0/