Primary amine catalyzed aldol reaction of isatins and acetaldehyde
作者:Qunsheng Guo、John Cong-Gui Zhao
DOI:10.1016/j.tetlet.2012.01.108
日期:2012.4
alkaloid-derived chiral primary amines were applied as the catalyst for the cross aldol reaction of isatins with acetaldehyde. With the quinine-derived amine catalyst 3, the desired aldol products were obtained in high yields and good enantioselectivities (up to 93% ee) under the optimized conditions. Although other enolizable aldehydes and ketones may also be applied in this reaction, the ee values obtained
Enantioselective organocatalytic aldol reaction of unactivated ketones with isatins
作者:Suresh Allu、Nagaraju Molleti、Ramachandrarao Panem、Vinod K. Singh
DOI:10.1016/j.tetlet.2011.05.013
日期:2011.8
Enantioselectiveorganocatalytic direct aldol reaction of unactivated ketones with various isatin derivatives was developed using cinchonine based urea ligand employing a noncovalent catalysis mechanism. Using this protocol we can access functionalized 3-alkyl-3-hydroxyindolin-2-ones in high yields with good to excellent enantioselectivities.