Highly Enantioselective [2+2]-Cycloaddition Reactions Catalyzed by a Chiral Aluminum Bromide Complex
作者:Eda Canales、E. J. Corey
DOI:10.1021/ja0765262
日期:2007.10.1
Enantioselective [2+2]-cycloaddition pathways to chiral cyclobutanes are rare and not generally utilized for synthesis. A new cycloaddition reaction of vinyl ethers with trifluoroethyl acrylate in the presence of a catalytic amount of chiral oxazaborolidine−AlBr3 complex is described which affords [2+2]-adducts with excellent yields and enantioselectivities. Applications of these adducts to the synthesis
Enantioselective Synthesis of Homologous Methyl-Substituted Bicyclic Enones Through Michael-Type Alkylation of Chiral Imines
作者:Virginie Goubaud、Robert Azerad
DOI:10.1080/00397919608003696
日期:1996.3
Abstract The preparation of 4a-methyl-substituted bicyclic enones in high enantiomeric purity is described, involving a Michael alkylation of (R)- or (S)-1-phenylethyl imines of the corresponding (±)-2-methylcyclopentanone, 2-methyl-cyclohexanone, 2-methylcycloheptanone, and 2-methylcyclooctanone with methyl vinyl ketone.