화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.136, No.34, 11890-11893, 2014
Hydroxyproline-Derived Pseudoenantiomeric [2.2.1] Bicyclic Phosphines: Asymmetric Synthesis of (+)- and (-)-Pyrrolines
We have prepared two new diastereoisomeric 2-aza-5-phosphabicyclo[2.2.1]heptanes from naturally occurring trans-4-hydroxy-L-proline in six chemical operations. These syntheses are concise and highly efficient, with straightforward purification. When we used these chiral phosphines as catalysts for reactions of gamma-substituted allenoates with imines, we obtained enantiomerically enriched pyrrolines in good yields with excellent enantioselectivities. These two diastereoisomeric phosphines functioned as pseudoenantiomers, providing their chiral pyrrolines with opposite absolute configurations.