SO_4^(2-)/TiO_2固体酸协同金鸡纳碱奎尼丁催化不对称Mannich反应

Utilization of Solid Acid SO_4^(2-)/TiO_2 Cooperated with Cinchona Alkaloid Quinidine to Asymmetric Mannich Organocatalysis

采用固体酸SO 2-4/Ti O2与金鸡纳碱奎尼丁[Quinidine(R)]进行负载,制备出具有较强氢键供体的SO 2-4/Ti O2/Quinidine(R)手性催化剂,并对比了金鸡纳碱奎尼丁及其衍生物金鸡纳碱奎尼丁-硫脲在不对称Mannich有机催化中的催化活性.实验结果显示:在相同的催化条件下,SO 2-4/Ti O2/quinidine(R)在不对称Mannich催化反应的催化活性性能高于金鸡纳碱奎尼丁,低于金鸡纳碱奎尼丁-硫脲.同时,通过催化条件优化,SO 2-4/Ti O2/quinidine(R)催化剂在间二甲苯为溶剂、-40℃及搅拌72 h的催化条件下,可获得具有较高光学活性的手性β-氨基酸酯类衍生物(89%~95%ee).

Via combination of solid acid SO 2-4 /Ti O2 with cinchona alkaloid quinidine（R）, the chiral catalyst of SO 2-4 /Ti O2/quinidine（R） carrying strong hydrogen-bonding donor has been obtained, which was evaluated on catalytic activity in the asymmetric organocatalysis, as comparing with quinidine（R） and thiourea-quinidine（R） derived from cinchona alkaloids. The result obviously showed that under the same conditions, the catalytic activity of SO 2-4 /Ti O2/quinidine（R） is more than that of quinidine（R）, but less than that of thiourea-quinidine（R）. Simultaneously, chiral β-amino ester derivatives with high optical activities were afforded under the optimum conditions of m-xylene as solvent and stirring for 72 h at-40 ℃. The value of ee was allowed to be the range of 89%~95%.