Asymmetric Copper(I)-Catalyzed Henry Reaction with an Aminoindanol-Derived Bisoxazolidine Ligand
作者:Kimberly Yearick Spangler、Christian Wolf
DOI:10.1021/ol9018612
日期:2009.10.15
Bisoxazolidine 1 is an effective ligand In the Me2Zn-promoted and the Cu(I)-catalyzed Henry reaction. While a wide range of nitroaldol products are obtained in high yields and ee's in both cases, the replacement of dimethylzinc with copper(l) acetate results in a complete reversal of the sense of asymmetric induction. The Cu(I)-catalyzed enantioselective addition of nitromethane to methyl 4-oxobutanoate followed by hydrogenation and spontaneous lactamization gives (S)-5-hydroxypiperidin-2-one in 72% overall yield and 98% ee which compares favorably with previously reported methods.
Merging Asymmetric Henry Reaction with Organocatalytic Cascade Reaction for the Construction of a Chiral Indolizidine Alkaloid Skeleton
作者:Yirong Zhou、Qin Yang、Jian Shen、Xin Chen、Yiyuan Peng、Yuefa Gong
DOI:10.1021/jo502379v
日期:2015.2.6
A sequential reaction combining the copper-catalyzed asymmetric Henry reaction with the organocatalytic Michael addition–hemiacetalization cascade reaction was developed. The C1-symmetric chiral diamine L1–copper complex was responsible for the first highly enantioselective Henry reaction, while diphenylprolinol silyl ether A acted as effective organocatalyst for the second cascade reaction between