Organocatalytic enantioselective hydrophosphonylation of ketimines usingcinchonaalkaloids and Na(2)CO(3) afforded products with high enantioselectivity. Both enantiomers of alpha-amino phosphonates can be prepared by using pseudoenantiomeric cinchonaalkaloids. The catalyst loading of cinchonaalkaloids can be reduced to 0.5 mol % without a significant loss of enantioselectivity.
Enantioselective Reaction of 2<i>H</i>
-Azirines with Phosphite Using Chiral Bis(imidazoline)/Zinc(II) Catalysts
作者:Shuichi Nakamura、Daiki Hayama
DOI:10.1002/anie.201704133
日期:2017.7.17
The first highly enantioselective nucleophilic addition reaction of phosphites with 2H‐azirines has been developed. The reaction was applied to various 3‐substituted 2H‐azirines using novel chiralbis(imidazoline)/ZnII catalysts to afford products in good yield with high enantioselectivity. The transformation of the obtained optically active aziridines showed that 2H‐azirines act as either α,β‐ or