L-脯氨酰胺催化剂的制备及其不对称催化性能研究

Study on the synthesis and asymmetric catalytic performance of the prolinamides

以廉价易得的脯氨酸和异斯特维醇为原料,合成了1a-b两种脯氨酰胺催化剂,并通过IR、~1H NMR、^(13)C NMR、HR-MS等方法对中间产物和目标产物的结构进行了表征。通过与邻硝基苯甲酸的反应,成功将中间产物16-氨基异斯特维醇乙酯的两种非对映异构体分离。初步考察了所合成催化剂对Aldol反应的不对称催化性能,得到很高的催化活性(转化率98%)和较好的立体选择性(anti/syn:83/17,ee值81%)。

In this work,two new prolinamides with isosteviol skeleton were designed and synthesized through simple coupling L-proline with isosteviol derivatives.The two diastereoisomers of 16 amino ethyl isosteviol were successfully separated.With only 5 mol%loading,the synthesized catalysts showed excellent activity(up to 98%yield)and good stereoselectivity(up to 83∶17 dr,81%ee)for the direct aldol reaction of cyclohexanone and substituted benzaldehydes at room temperature.