Asymmetric Aldol Reaction of 3-Acetyl-2H-chromen-2-ones and Isatins Catalyzed by a Bifunctional Quinidine Urea Catalyst.
The asymmetric aldol reaction of 3-acetyl-2H-chromen-2-ones and isatins has been realized by using a bifunctional quinidine-derived urea as the catalyst. The corresponding 3-hydroxyoxindole derivatives containing a 2H-chromen-2-one moiety were obtained in good yields and high enantioselectivities. When (Z)-ethyl 2-benzylideneacetoacetate was used as the substrate, a mixture of two diastereomers (bothZandE) was obtained due to the isomerization of the double bond under the reaction conditions.
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698. ;
Santhi
S
Abbaraju
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698. ;
John Cong-Gui
JC
Zhao
3-acetyl-2H-chromen-2-one; aldol reaction; asymmetric catalysis; bifunctional catalyst; enolate; isatin