壳聚糖负载辛可宁催化剂的制备及其在水中催化不对称Aldol反应

摘要

以丁二酸酐为连接臂，经两步反应制备了壳聚糖负载辛可宁有机催化剂(CTS-SA-CN)，并研究了CTS-SA-CN在水体系中对酮与多种芳香醛的直接不对称aldol反应的催化性能。结果表明，在CTS-SA-CN催化下，酮与多种芳香醛发生直接不对称aldol反应，可得到99%的产率和96%的ee值。另外， CTS-SA-CN可通过简单过滤实现回收，重复使用5次活性并没有明显下降。%Chitosan‐supported succinic anhydride‐cinchonine (CTS‐SA‐CN) was synthesized via a two‐step route with succinic anhydride as the linker. The catalyst was used to promote the direct asymmetric aldol reaction between cyclohexanone and a variety of aromatic aldehydes in aqueous medium. Aldol adducts were obtained in excellent yields (up to 99%) and good enantioselectivities (up to 96%ee). The CTS‐SA‐CN catalyst was successfully recycled simply by filtration after use, and was reused 5 times without any significant loss of activity.