Development of L-Proline-Based Chiral Ionic Liquids for Asymmetric Michael Reaction

Autor: Karolina Zalewska, Isabel Pinto, Luis Cabrita, Małgorzata E. Zakrzewska, João P. Noronha, M. Nunes da Ponte, Luis C. Branco
Přispěvatelé: LAQV@REQUIMTE, DQ - Departamento de Química
Rok vydání: 2023
Předmět:
Zdroj: Catalysts
Volume 13
Issue 2
Pages: 270
ISSN: 2073-4344
DOI: 10.3390/catal13020270
Popis: co-financed by the ERDF under the PT2020 Partnership agreement (POCI-01-0145-FEDER–007265) The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by the Infrastructure Project N◦ 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC). Different Chiral Ionic Liquids (CIL) based on L-proline have been developed. Simple and efficient synthetic methodologies are used, allowing preparation in good yields for twelve novel CILs using L-proline as a cation or anion combined with suitable counter-ions. A detailed physical and chemical characterization of the CILs was performed to evaluate the influence of counter-ions on the final properties. The most promissory CILs were tested as efficient chiral catalysts in IL media for asymmetric Michael addition reactions of ketones and aldehydes to nitro-olefins. Similar or even better conversions and enantioselectivities (ee up to 95%) compared to the original L-proline were achieved. Additionally, a good product extraction performance using supercritical CO2 processes was obtained. publishersversion published
Databáze: OpenAIRE
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