We successfully developed the first enantioselective trifluoromethylthiolation of 4-substituted pyrazolones catalyzed by amide-based Cinchona alkaloids with N-trifluoromethylthiosaccharin. A broad variety of chiral CF3S-pyrazolones were obtained in excellent yields with high enantioselectivities. Controlled experiments showed that the multiple hydrogen bonding interactions and the steric hindrance
我们成功开发了第一个由
酰胺类
金鸡纳
生物碱与 N-三
氟甲
硫基
糖精催化的 4-取代
吡唑啉
酮的对映选择性三
氟甲
硫基化反应。以优异的产率和高对映选择性获得了多种手性CF 3 S-
吡唑啉
酮。对照实验表明,多
重氢键相互作用和 NH 位位阻对于高对映选择性和反应活性是不可或缺的。此外,这些基于
酰胺的相转移
催化剂可以很容易地回收并重新用于此类反应,并且具有几乎原始的反应性和对映选择性。