硅胶负载型离子液体催化合成β-烯胺酮

Synthesis of β-enaminones over silica-confined ionic liquids

采用溶胶凝胶法制备了一系列硅胶负载型离子液体催化剂,利用红外光谱(FT-IR)和电子扫描电镜(SEM)对催化剂的物理化学性质进行了表征,并考察其在室温无溶剂条件下催化合成β-烯胺酮的性能。结果表明:固载后的离子液体的实际用量显著减少,催化活性显著提高,其中[bmim]BF_4/silica和[bmim]PF_6/silica显示高的催化活性,在室温无溶剂条件下反应时间30 min后,β-烯胺酮收率分别达到93.6%和92.2%。此外,硅胶负载离子液体易于分离,循环使用四次后,其催化活性无明显降低。

Several silica-confined ionic liquids （SCILs）were synthesized by sol-gel method and characterized by FT-IR and SEM methods. The catalytic performance of these catalysts for the synthesis of β-enaminone was also investigated. Results showed that sil- ica-confined could both greatly reduce the amount ionic liquid used and increase the catalytic activity. Among all the catalysts test- ed, [ bmim] BFJsilica and[ bmim] PF6/silica were proven to be the most efficient since the reaction could be carried out with ex- ceLlent yield of 93.6 and 92. 2%, respectively, under room temperature and solvent-free condition for 0. 5 h. Furthermore, [ bmim ] BF4/silica was conveniently separated from the products and reused four times without considerable loss of activity.