Direct Asymmetric Aldol Reaction Co-catalyzed by Amphiphilic Prolinamide Phenol and Lewis Acidic Metal on Water
作者:Tao Zhang、Yunxiao Zhang、Zaichun Li、Zhongtai Song、Hao Liu、Jingchao Tao
DOI:10.1002/cjoc.201201017
日期:2013.2
An approach based on combinations of various water compatible Lewis acids and lipophilic group containing amphiphilic prolinamide co‐catalysts has been evaluated for the direct asymmetric Aldol reaction. From the broad screening of chloride salts from alkali metal to transition metal, LiCl, ZnCl2 and SnCl2 lead to the highest stereoselectivities. The optimized catalytic conditions (10 mol% prolinamide
已评估了一种基于各种水溶性路易斯酸和含有亲脂基团的两亲脯氨酰胺助催化剂的组合方法,用于直接不对称Aldol反应。从从碱金属到过渡金属的氯化物盐的广泛筛选,LiCl,ZnCl 2和SnCl 2导致最高的立体选择性。与基于prolinamide活化的中等立体选择性方法相比,优化的催化条件(10 mol%脯氨酰胺与10 mol%MCl 2或室温下在水中的20 mol%LiCl)可提供具有改进的对映选择性(高达99%ee)的反产物。只要。