Heterogeneous organocatalysis at work: functionalization of hollow periodic mesoporous organosilica spheres with MacMillan catalyst
- Resource Type
- Authors
- Qiong Wang; Zhi Jun Li; Jiao Yi Shi; Chang An Wang; Yuan Zhang; Wei Wang
- Source
- Chemistry (Weinheim an der Bergstrasse, Germany). 17(22)
- Subject
- Molecular Structure
Chemistry
Organic Chemistry
Enantioselective synthesis
Water
Stereoisomerism
General Chemistry
Heterogeneous catalysis
Silicon Dioxide
Catalysis
Mesoporous organosilica
Surface-Active Agents
Chemical engineering
Phenylene
Organocatalysis
Click chemistry
Organic chemistry
Nanoparticles
Click Chemistry
Enantiomeric excess
Palladium
- Language
- ISSN
- 1521-3765
We report a new method for the synthesis of hollow-structured phenylene-bridged periodic mesoporous organosilica (PMO) spheres with a uniform particle size of 100-200 nm using α-Fe(2)O(3) as a hard template. Based on this method, the hollow-structured phenylene PMO could be easily functionalized with MacMillan catalyst (H-PhPMO-Mac) by a co-condensation process and a "click chemistry" post-modification. The synthesized H-PhPMO-Mac catalyst has been found to exhibit high catalytic activity (98% yield, 81% enantiomeric excess (ee) for endo and 81% ee for exo) in asymmetric Diels-Alder reactions with water as solvent. The catalyst could be reused for at least seven runs without a significant loss of catalytic activity. Our results have also indicated that hollow-structured PMO spheres exhibit higher catalytic efficiency than solid (non-hollow) PMO spheres, and that catalysts prepared by the co-condensation process and "click chemistry" post-modification exhibit higher catalytic efficiency than those prepared by a grafting method.