Chiral aminophosphines derived from hydroxyproline and their application in allene–imine [4 + 2] annulation
作者:San N. Khong、Changmin Xie、Xinyi Wang、Hao Tan、Ohyun Kwon
DOI:10.1038/s41429-019-0181-0
日期:2019.6
A robust synthetic route from l-hydroxyproline (l-Hyp) to phosphines has established an expandable library of six chiral aminophosphines, which were then applied to the phosphine-catalyzed [4 + 2] allene–imine annulation. The enantioinduction in the annulations—induced by a purely steric effect—were moderate (up to 57% ee). A switch of the reaction site from the γ- to the β′-carbon atom of the allenoate
Try bifunctional aminophosphines! An asymmetric organocatalytic [4+2] cycloaddition between α‐substituted allenoates and tosylaldimines using bifunctional N‐acyl aminophosphine catalysts was described (see scheme). This operationally simple catalytic system could provide valuable complementary results to those of the monodentate phosphine system.