A new series of Schiff bases derived from Cinchona alkaloids were developed as chiral ligands for the copper(II)-catalyzed asymmetricHenry reaction. The optimized catalyst can promote the Henry reaction of both aromatic and aliphatic aldehydes with nitromethane or nitroethane. Those reactions can afford the chiral β-nitro alcohol adducts with high enantioselectivities.
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.
Brucine-Derived Amino Alcohol Catalyzed Asymmetric Henry Reaction: An Orthogonal Enantioselectivity Approach
作者:Hun Young Kim、Kyungsoo Oh
DOI:10.1021/ol902380z
日期:2009.12.17
A new approach to both enantioenriched Henry products is developed by use of different molecularities of metal-ligand complexes generated from Cu(I) and Zn(II) metals with readily available chiral amino alcohol 1.
Keratin Protein-Catalyzed Nitroaldol (Henry) Reaction and Comparison with Other Biopolymers
DMSO and in water in the presence of tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. Negligible background reactions (i.e., negative control experiment in the absence of keratin protein) were observed in these solvent systems. Aromatic aldehydes bearing electron-donating groups and aliphatic aldehydes showed poor or no conversion, respectively. In general, the reactions in water/TBAB