A novel N-acetophenone cinchona ammonium salts as chiral phase transfer catalysts for the alkylation of Schiff base in water

Novel N-acetophenone cinchona ammonium salts have been successfully synthesized and used as chiral phase transfer catalysts for the asymmetric alkylation of tert-butyl benzophenone Schiff base derivatives in aqueous media at room temperature with the highest ee and yield up to 96 and 98%, respectively. We have also studied the influence of substituted acetophenone groups in quaternary ammonium salts derived from the cinchona alkaloids.

Graphical abstractNovel N-acetophenone cinchona ammonium salts have been successfully synthesized and used as chiral phase transfer catalysts for the asymmetric alkylation of tert-butyl benzophenone Schiff base derivatives in aqueous media at room temperature with highest ee and yield up to 96 and 98%, respectively. We have also studied the influence of substituted acetophenone groups in quaternary ammonium salts derived from the cinchona alkaloids. Figure optionsDownload full-size imageDownload as PowerPoint slide