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Chirally functionalized SBA-15 as efficient heterogeneous catalyst for asymmetric ketone reduction
Umesh Balakrishnan1, Sivan Velmathi
1Organic and Polymer Synthesis Laboratory, Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015, Tamilnadu, India.
Journal of Nanoscience and Nanotechnology
|June 15, 2013
Summary
A novel chiral amine catalyst immobilized on SBA-15 efficiently reduces prochiral ketones, yielding secondary alcohols with up to 79% enantiomeric excess. The supported catalyst demonstrates excellent recyclability for sustainable chemical synthesis.
Area of Science:
- Organic Chemistry
- Materials Science
- Catalysis
Background:
- Chiral amine catalysts are crucial for asymmetric synthesis.
- Immobilization of catalysts can enhance stability and recyclability.
- Mesoporous materials like SBA-15 offer high surface area for catalyst support.
Purpose of the Study:
- To synthesize and immobilize a chiral amine catalyst derived from (1R, 2S)-(-)-norephedrine.
- To characterize the immobilized catalyst using various physico-chemical techniques.
- To evaluate the catalytic performance of the supported catalyst in prochiral ketone reduction.
Main Methods:
- Reductive amination of (1R, 2S)-(-)-norephedrine and 5-chlorosalicylaldehyde.
- Immobilization onto SBA-15 using 3-chloropropyltrimethoxysilane.
- Characterization via NMR, XRD, SEM, N2 adsorption, FTIR, and UV-DRS.
- Catalytic reduction of prochiral ketones using boranedimethylsulphide.
Main Results:
- Successful synthesis and immobilization of the chiral amine catalyst onto SBA-15.
- Comprehensive characterization confirmed the catalyst's structure and properties.
- Achieved up to 79% enantiomeric excess in the reduction of selective ketones.
- Demonstrated high catalytic activity and recyclability of the immobilized catalyst.
Conclusions:
- The immobilized chiral amine catalyst is effective for asymmetric ketone reduction.
- SBA-15 serves as a suitable support for enhancing catalyst performance and reusability.
- This work provides a promising approach for developing efficient and recyclable chiral catalysts.
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