TY - JOUR
T1 - Immobilisation of L-proline onto mixed-linker zirconium MOFs for heterogeneous catalysis of the aldol reaction
AU - Mutiah, Mutiah
AU - Rochat, Sebastien
AU - Amura, Ida
AU - Burrows, Andrew D.
AU - Emanuelsson, Emma A.C.
N1 - Funding Information:
The authors thank the University of Bath for the PhD scholarship, the Department of Chemical Engineering and the Department of Chemistry for technical support.
Publisher Copyright:
© 2021 Elsevier B.V.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/1/30
Y1 - 2021/1/30
N2 - Novel heterogeneous catalysts based on zirconium sulfonated metal-organic framework (MOF)-supported L-proline has been developed for the asymmetric aldol reaction. In this study, a chiral zirconium-based sulfonated MOF-proline was assembled through the solvothermal reaction of ZrCl4 with a combination of benzene-1,4-dicarboxylic acid (H2bdc) and sodium 4-carboxy-2-sulfobenzoate (H2bdc-SO3Na) in the presence of L-proline. The MOF showed excellent crystallinity, high porosity and thermal stability, making it an attractive catalyst for the aldol reaction since the bifunctionality can be enhanced to act both as Brønsted acid and Lewis base active sites. The reaction between acetone and two different aldehydes was investigated and the catalyst showed good activity and enantioselectivity, especially in the reaction with 4-nitrobenzaldehyde (83 % enantiomeric excess and 85 % conversion). The reusability of the catalyst was evaluated by organic solvent nanofiltration membranes. After three successive aldol reactions, the enantiomeric excess and conversion reaction of the catalyst showed only slight decreases, confirming good recyclability. Moreover, scale-up of the organic solvent nanofiltration membrane operation is relatively simple, promoting ease of operation on an industrial scale.
AB - Novel heterogeneous catalysts based on zirconium sulfonated metal-organic framework (MOF)-supported L-proline has been developed for the asymmetric aldol reaction. In this study, a chiral zirconium-based sulfonated MOF-proline was assembled through the solvothermal reaction of ZrCl4 with a combination of benzene-1,4-dicarboxylic acid (H2bdc) and sodium 4-carboxy-2-sulfobenzoate (H2bdc-SO3Na) in the presence of L-proline. The MOF showed excellent crystallinity, high porosity and thermal stability, making it an attractive catalyst for the aldol reaction since the bifunctionality can be enhanced to act both as Brønsted acid and Lewis base active sites. The reaction between acetone and two different aldehydes was investigated and the catalyst showed good activity and enantioselectivity, especially in the reaction with 4-nitrobenzaldehyde (83 % enantiomeric excess and 85 % conversion). The reusability of the catalyst was evaluated by organic solvent nanofiltration membranes. After three successive aldol reactions, the enantiomeric excess and conversion reaction of the catalyst showed only slight decreases, confirming good recyclability. Moreover, scale-up of the organic solvent nanofiltration membrane operation is relatively simple, promoting ease of operation on an industrial scale.
KW - Enantioselectivity
KW - Metal-organic framework
KW - Mixed-linker
KW - Proline
KW - Reusability
UR - http://www.scopus.com/inward/record.url?scp=85100604368&partnerID=8YFLogxK
U2 - 10.1016/j.cep.2021.108315
DO - 10.1016/j.cep.2021.108315
M3 - Article
AN - SCOPUS:85100604368
VL - 161
JO - Chemical Engineering & Processing: Process Intensification
JF - Chemical Engineering & Processing: Process Intensification
SN - 0255-2701
M1 - 108315
ER -