Enantioselective Hydrophosphonylation of Ketimines Using Cinchona Alkaloids

Significance

A catalytic enantioselective hydrophosphonylation of ketimines using cinchona ­alkaloid catalysts is presented. The authors obtained products 1 in high yields with excellent enantioselectivities. The 2,4,6-trimethylbenzenesulfonyl group was introduced to enhance the reactivity of ketimines, and could be removed easily without loss of enantiomeric purity. According to the proposed transition state 2, the catalyst not only coordinates the ketimine but also enhances the nucleophilicity of sodium phosphate by coordination with the sodium ion.