Poly(imidazolium) Carbosilane Dendrimers: Synthesis, Catalytic Activity in Redox Esterification of α,ß-Unsaturated Aldehydes and Recycling via Organic Solvent Nanofiltration

0547595 - ÚCHP 2022 RIV CH eng J - Journal Article
Krupková, Alena - Kubátová, L. - Červenková Šťastná, Lucie - Cuřínová, Petra - Müllerová, Monika - Karban, Jindřich - Čermák, Jan - Strašák, Tomáš
Poly(imidazolium) Carbosilane Dendrimers: Synthesis, Catalytic Activity in Redox Esterification of α,ß-Unsaturated Aldehydes and Recycling via Organic Solvent Nanofiltration.
Catalysts. Roč. 11, č. 11 (2021), č. článku 1317. E-ISSN 2073-4344
Institutional support: RVO:67985858
Keywords : immobilization * organocatalysis * N-heterocyclic carbenes * umpolung * poly(cationic) dendrimers * nanofiltration
OECD category: Organic chemistry
Impact factor: 4.501, year: 2021
Method of publishing: Open access
https://www.mdpi.com/2073-4344/11/11/1317

Three series of poly(ionic) carbosilane dendrimers peripherally functionalized with imidazolium groups substituted on N-3 with methyl, isopropyl and 2,6-diisopropylphenyl (Dipp) were prepared up to the 3rd generation together with model monovalent imidazolium iodides and used as N-heterocyclic carbene (NHC) precursors. Catalytic activity of model and dendritic NHCs generated in situ by deprotonation with DBU was tested in redox esterification of α,β-unsaturated aldehydes and the influence of substitution, dendrimer generation, temperature and substrate structure on the reaction outcome was evaluated. Dipp substituted NHCs showed high activity and selectivity in the reaction with primary alcohols. Effectiveness of organic solvent nanofiltration for the recycling of dendritic NHCs was demonstrated on the 1st generation Dipp substituted catalyst in model redox esterification of cinnamaldehyde with benzyl alcohol. A marked increase in both activity and selectivity in the first four reaction runs was observed and this improved performance was preserved in the following catalytic cycles.
Permanent Link: http://hdl.handle.net/11104/0323807