Synthesis of planar chiral [2.2]paracyclophane-based amino thioureas and their application in asymmetric aldol reactions of ketones with isatins
作者:Yu Lu、Yudao Ma、Shaobo Yang、Manyuan Ma、Hongju Chu、Chun Song
DOI:10.1016/j.tetasy.2013.07.023
日期:2013.9
were used as bifunctionalcatalysts for organocatalytic enantioselective aldolreactions between ketones and isatins, affording the desired adducts containing a chiral tertiary alcohol in high yields (up to 92% yield) and with good enantioselectivity (up to 88% ee). This is a successful example of employing planar chiral [2.2]paracyclophane-based amino thioureas in asymmetricaldolreactions.
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.