Asymmetric Direct Vinylogous Michael Reaction Catalyzed by Self-Assembled Organocatalyst
作者:Wei-Yi Chen、Luo Ouyang、Rui-Ye Chen、Xin-Sheng Li
DOI:10.1080/00397911.2011.563023
日期:2012.9
Abstract The self-assembled organocatalyst of cinchonaalkaloidderivatives and amino acids has been applied to a direct asymmetric vinylogous Michael addition of α,α-dicyanoolefins to nitroolefins; the corresponding products could be obtained in moderate to good yields and enantioselectivities. GRAPHICAL ABSTRACT
chiral thiourea-tertiary amine organocatalysts have been applied to a direct asymmetric vinylogousMichaeladdition of α,α-dicyanoolefins to nitroolefins with 2–10 mol % catalyst loadings. The electronic properties of the thiourea-based catalysts have significant influences on this reaction. Moderate to excellent enantioselectivities (57–95% ee) have been achieved with low to good isolated yields through