Efficient and Convenient Synthesis of Ionic Liquid Supported SBA-15 Mesoporous Srganosilica and Its Beneficial Applications in Henry Reaction

Abstract

Compared with post-grafting method, a novel and controllable strategy is applied to introduce highly dispersed ionic liquid species into mesoporous SBA-15 silica, providing simpler synthesis steps, more uniform surface coverage and higher loading of ionic liquid, with fewer raw materials. Basic task-specific ionic liquids are synthesized and characterized by X-ray diffraction, N 2 adsorption-desorption, thermogravimetry and fourier transform infrared spectroscopy. The results showed that the catalysts, prepared by co-condensation method, have better ordered mesostructure and higher loading of ionic liquid than those by post-grafting approach. Meanwhile, the catalysts exhibit much higher activity than those by post-grafting approach in Knoevenagel condensation. Furthermore, these supported catalysts are also proven to be efficient and reusable in Henry reaction under solvent-free conditions.

Synthesis and Catalytic Activity of Novel Heternuclear Dication Brønsted Acidic Ionic Liquids

“…如室温离子液体作为溶剂, 使催化系 统具有极高的稳定性, 用于不同钯催化剂催化 Suzuki 反 应 [4] 及 Cr(III)-Al 2 O 3 支载型催化剂催化由果糖制备 5-羟 基糠醛反应 [5] ; 可作为染料敏感太阳能电池的电解质溶 液, 为电池反应提供稳定的碘源 [6] ; 作为辅助激光解析 电离质谱中的基质, 可高效提高寡糖/糖肽的离子化率, 从而提高了仪器的检测灵敏度 [7] ; 通过"稼接"法将离 子液体连接在用于混合模式高效液相色谱固定相的多 孔聚合物整体柱中, 可有效改进 HPLC 的分离容量和效 率 [8] ; 将离子液体作为模板分子制备成表面印迹聚合物, 可对该模板分子及其结构类似物有高度的选择性识别 作用, 实际应用于废水中离子液体的回收 [9] 等. 直接作 催化剂的离子液体可用于水相中催化二茂铁醇的类 Friedel-Crafts 反应 [10] , 碱性聚合型离子液体用于催化 Claisen-Schmidt 缩合反应 [11] , 以及新型固载型碱性离子 液体用于催化 Henry 反应 [12] 、三烷基胺 [18] 、2-吡咯烷酮 [19] 和吗啉 [20] 等单磺酸基, 以及基于三亚乙基二胺 [21] 、咪唑 [22] 、双咪唑 [23] 和双吡 咯 [24] 、哌嗪 [16] 双磺酸基功能化酸性离子液体在内, 均来 源于已商品化的常见含氮杂环内核化合物的直接磺酸 功能化, 取材受限, 总体数量还相对较少. 因此, 磺酸 功能化酸性离子液体的开发还有很大的发展空间.…”