Preparation of L-Proline Functionalized SBA-15 as Catalysts for Asymmetric Aldol Addition

• Main Authors: Chia-Ming Yang, 楊嘉銘
• Other Authors: 鄭淑芬
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/25017383263767974266

碩士 === 臺灣大學 === 化學研究所 === 98 === L-Proline is known as an organocatalyst for asymmetric Aldol reaction. For the purpose of easy separation and reuse of the catalyst, L-proline was immobilized onto mesoporous silica to form heterogeneous catalyst through thiol-ene addition using AIBN as the initiator. Cis-4-mercapto-L- proline (SH-proline) was synthesized from trans-4-hydroxy-L-proline. Vinyl group functionalized SBA-15 (briefly termed vinyl-SBA-15) was prepared by co-condensation of tetraethyl orthosili- cate (TEOS) and vinyltrimethoxysilane (VTMS) using P123 copolymer as the pore directing agent in strong acidic environment. XRD patterns showed that the materials contained well-ordered mesopores arranged in 2-D hexagonal arrays. N2 sorption data showed their surface area, pore volume, and pore diameter decreased after L-proline was immobilized. Sulfur K-edge XANES spectra showed the existence of C-S-C bond. 13C CP/MAS solid state NMR showed the existence of proline structure. SEM and TEM images showed the morphologies and mesoporosity didn’t change after poline was immobilized. The SBA-15 immobilized L-proline materials were used as catalysts in the asymmetric Aldol reaction. The pH value of pre-treatment solution, reaction solvent, and temperature were found to affect the chiral selectivity drastically.