Core–shell silica magnetic microspheres supported proline as a recyclable organocatalyst for the asymmetric aldol reaction
作者:Honglei Yang、Shuwen Li、Xiaoyu Wang、Fengwei Zhang、Xing Zhong、Zhengping Dong、Jiantai Ma
DOI:10.1016/j.molcata.2012.07.017
日期:2012.11
enantioselectivity (up to 80%) in the asymmetric aldol reaction between aldehyde acceptors and ketone donors. On the other hand, the synthesized catalyst could be rapidly separated from the reaction mixture through an external magnetic field and reused up to five runs without any obvious loss of activity, indicating its easy-separated property and excellent recyclability.
l-4-羟基脯氨酸已成功嫁接到核-壳结构二氧化硅磁性微球上,并通过元素分析,热重分析(TGA),振动样品磁法(VSM),高分辨率透射电子显微镜(HRTEM)和傅里叶变换红外光谱进行了表征(FT-IR)。手性固定化催化剂在醛受体与酮供体之间的不对称羟醛反应中表现出高催化活性(高达92%),非对映选择性(高达85:15)和对映选择性(高达80%)。另一方面,合成的催化剂可以通过外部磁场从反应混合物中快速分离出来,并重复使用多达五次,而活性没有任何明显的损失,这表明其易于分离,并且具有出色的可回收性。