Diaminomethylenemalononitrile organocatalyst 5 promotes the asymmetric conjugate addition of branched aldehydes to vinyl sulfone to afford the corresponding adducts with all-carbon quaternary stereocenters in excellent yields with up to 91% ee.
Asymmetric conjugate additions of branched aldehydes to vinyl sulfones promoted by sulfonamide organocatalyst 6 or 7 have been developed, allowing facile synthesis of the corresponding adducts with all-carbon quaternary stereocenters in excellent yields with up to 95% ee.
Design of Structurally Rigid <i>trans</i>-Diamine-Based Tf-Amide Organocatalysts with a Dihydroanthracene Framework for Asymmetric Conjugate Additions of Heterosubstituted Aldehydes to Vinyl Sulfones
作者:Shin A. Moteki、Senmiao Xu、Satoru Arimitsu、Keiji Maruoka
DOI:10.1021/ja107897t
日期:2010.12.8
Asymmetric conjugateaddition of α-heterosubstituted aldehydes such as α-amido and α-alkoxy aldehydes to vinylsulfone was effected under the influence of structurally rigid trans-diamine-based Tf-amido organocatalyst (S,S)-2 with a dihydroanthracene framework to furnish α,α-dialkyl(amido)aldehydes and α,α-dialkyl(alkoxy)aldehydes with high enantioselectivity. The chiral efficiency of the structurally