壳聚糖负载L-脯氨酸对水中不对称Aldol反应的催化性能

以壳聚糖为载体制备了负载型L-脯氨酸不对称催化剂;将合成产物用于催化丙酮与取代苯甲醛在水中的直接不对称Aldol反应,考察了其催化性能.结果表明,与在有机溶剂中的L-脯氨酸催化剂相比,在水相中的壳聚糖负载L-脯氨酸催化剂表现出更好的催化活性;就间硝基苯甲醛与丙酮在水中的不对称Aldol反应而言,壳聚糖负载L-脯氨酸催化下的产率和ee值分别达95%和48%.此外,壳聚糖负载L-脯氨酸催化剂在水中具有很好的重复使用性能,重复使用10次后相应的产率和ee值分别为88%和68%.

Catalytic performance of chitosan supported L-proline for asymmetric Aldol reaction in water

Asymmetric catalyst chitosan supported L-proline was prepared with chitosan as the supporter. As-synthesized product was used to catalyze the direct asymmetric reaction of ace tone and substituted benzaldehyde in water, and its catalytic performance was evaluated. Results indicate that, as compared with L-proline catalyst in organic solvent, chitosan supported L-proline catalyst shows better catalytic activity in water. Namely, in the presence of chitosan supported L-proline catalyst, a yield of 95% and an ee value of 48% are obtained for the asymmetric Aldol reaction between m-nitrobenzaldehyde and acetone. Besides, chitosan supported L-proline catalyst has good reusability in water; and a yield of 88% and an ee value of 68% are acquired in water even after the catalyst is reused for 10 cycles.