Synthesis of <i>C</i><sub>1</sub>-Symmetric Chiral Secondary Diamines and Their Applications in the Asymmetric Copper(II)-Catalyzed Henry (Nitroaldol) Reactions
作者:Yirong Zhou、Junfang Dong、Fanglin Zhang、Yuefa Gong
DOI:10.1021/jo102124d
日期:2011.1.21
A small library of C1-symmetric chiral diamines (L1−L9) was constructed via condensing exo-(−)-bornylamine or (+)-(1S,2S,5R)-menthylamine with various Cbz-protected amino acids. Among them, ligand L1/CuCl2·2H2O complex (2.5 mol %) shows outstanding catalytic efficiency for Henryreaction between a variety of aldehydes and nitroalkanes to afford the expected products in high yields (up to 98%) with
Camphor-derived C1-symmetric chiral diamine organocatalysts for asymmetric Michael addition of nitroalkanes to enones
作者:Yirong Zhou、Qiang Liu、Yuefa Gong
DOI:10.1039/c2ob25922b
日期:——
A series of stable C1-symmetric chiral diamines (2a–2l) were conveniently synthesized by condensing exo-(−)-bornylamine or (+)-(1S,2S,5R)-menthylamine with various commercially available Cbz-protected amino acids. Among them, 2a can efficiently promote the Michael addition of nitroalkanes to a broad scope of enones with high yields (up to 96%) and excellent enantioselectivities (up to 98%) under mild conditions.