Asymmetric Michael reactions catalyzed by a highly efficient and recyclable quaternary ammonium ionic liquid-supported organocatalyst in aqueous media
作者:Subrata K. Ghosh、Yupu Qiao、Bukuo Ni、Allan D. Headley
DOI:10.1039/c3ob27398a
日期:——
developed and successfully applied to the asymmetricMichaelreaction in the presence of a newly developed ionic liquid-supported (ILS) benzoic acid as co-catalyst. For the reactions studied, in which various aldehydes and nitroolefins were examined, excellent diastereo- and enantioselectivities were obtained with low catalyst loading. Also, the catalyst could be recycled for ten times without significant
Diarylprolinol Silyl Ether Salts as New, Efficient, Water-Soluble, and Recyclable Organocatalysts for the Asymmetric Michael Addition on Water
作者:Zilong Zheng、Benjamin L. Perkins、Bukuo Ni
DOI:10.1021/ja9093583
日期:2010.1.13
for the catalytic asymmetric Michaeladdition of aldehydes to nitroolefins on water has been developed and provided the Michael adducts in excellent diastereo- and enantioselectivities. A notable feature of these organocatalysts is that they can be recycled for more than six times without a significant loss of catalytic activity and stereochemical control. In addition, the synthetic procedure presented