Unprecedented NNC-Scorpionate Zirconium-based Bicomponent System for the Very Efficient CO2 Fixation into a Variety of Cyclic Carbonates
| Autor: | Fernández-Baeza, Juan, Sánchez-Barba, Luis F., Lara-Sánchez, Agustín, Sobrino, Sonia, Martínez-Ferrer, Jaime, Garcés, Andrés, Navarro, Marta, Rodríguez, Ana M. |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | BURJC-Digital. Repositorio Institucional de la Universidad Rey Juan Carlos instname |
| Popis: | Preprint Two new derivatives of the bis(3,5-dimethylpyrazol-1-yl)methane modified by introduction of organosilyl groups on the central carbon atom, one of which bearing a chiral fragment, have been easily prepared. We verified the potential utility of these compounds through the reaction with [Zr(NMe2)4] for the preparation of novel zirconium complexes in which an ancillary bis(pyrazol-1-yl)methanide acts as a robust monoanionic tridentate scorpionate in a κ3-NNC chelating mode, forming strained four-membered heterometallacycles. These κ3-NNC-scorpionate zirconium amides were investigated as catalysts in combination with tetra-n-butylammonium bromide as cocatalyst for CO2 fixation into five-membered cyclic carbonate products. The study has led to the development of an efficient zirconium-based bicomponent system for the selective cycloaddition reaction of CO2 with epoxides. Kinetics investigations confirmed apparent first-order dependence on the catalyst and cocatalyst concentrations. In addition, this system displays very broad substrate scope, including mono- and disubstituted substrates, as well as the challenging biorenewable terpene derived limonene oxide, under mild and solvent-free conditions. |
| Databáze: | OpenAIRE |
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