A Highly syn-Selective Nitroaldol Reaction Catalyzed by CuII-Bisimidazoline
作者:Liang Cheng、Jiaxing Dong、Jingsong You、Ge Gao、Jingbo Lan
DOI:10.1002/chem.201000650
日期:——
Catalyzing Henry: Chiral bisimidazoline 1–Cu(OTf)2, in the presence of N‐methylmorpholine as a base, was discovered to efficiently catalyze the nitroaldolreaction in a highly syn‐ and enantioselective manner for a broad range of aldehydes, including aromatic, heteroaromatic, α,β‐unsaturated, and aliphatic aldehydes (see scheme).
Chiral Tetraaminophosphonium Salt-Mediated Asymmetric Direct Henry Reaction
作者:Daisuke Uraguchi、Sawako Sakaki、Takashi Ooi
DOI:10.1021/ja075152+
日期:2007.10.1
Chiral tetraaminophosphonium salts 1 possessing the phosphorus-centered [5.5]-spirocyclic core have been designed and synthesized in a single step from L-valine-derived diamine. The three-dimensional molecular structure was successfully verified by the single-crystal X-ray diffraction analysis, which also identified a secondary interaction between the phosphonium cation and chloride ion via double hydrogen-bonding. The potential of this novel onium salt as a chiral organic molecular catalyst has been demonstrated in an application to asymmetric direct Henry reaction.