脯氨醇衍生物有机催化的不对称Oxaziridination反应

Asymmetric organocatalytic oxaziridination catalyzed by prolinol derivatives

目的筛选适用于不对称氧氮杂环丙烷化反应的有机催化剂体系。方法将6种脯氨醇衍生物催化剂用于芳香醛亚胺为底物,间氯过氧苯甲酸(m-CPBA)为氧化剂的不对称氧氮杂环丙烷化反应,考察溶剂、催化剂用量、温度及浓度等因素对反应立体选择性的影响。结果最佳催化条件为20 mmo L%催化剂1a,甲苯为溶剂,-40℃反应。用于10种不同取代芳香醛亚胺为底物的反应,得到了88%~95%的产率和最高达50%ee的立体选择性。结论脯氨醇衍生物催化剂催化不对称氧氮杂环丙烷化反应,得到了高效的产率和中等的对映选择性。

Objective To screen organocatalyst system in the asymmetric oxaziridination reaction. Methods Six proline derivatives were used to catalyze the asymmetric oxaziridination of aryl aldimine. The effects of solvent,temperature,catalyst amount and concentration were investigated on the enantioselectivities. Results The optimized conditions were confirmed to include toluene as the solvent with a 20 mol% loading of catalyst 1 a at-40 ℃. The screened catalyst system was applied in the reaction of 10 different aryl aldimine,the corresponding products were obtained in88% ~ 95% yield with up to 50% ee. Conclusion Proline derivatives catalyze the asymmetric oxaziridination reaction to get excellent yield and mild enantioselectivities.