Enantioselective Synthesis of Nitroalkanes Bearing All-Carbon Quaternary Stereogenic Centers through Cu-Catalyzed Asymmetric Conjugate Additions
作者:Jing Wu、Dawn M. Mampreian、Amir H. Hoveyda
DOI:10.1021/ja050800f
日期:2005.4.1
first examples of catalytic asymmetric conjugateaddition (ACA) of alkylzinc reagents to trisubstituted nitroalkenes, leading to the formation of nitroalkanes bearing a quaternary carbon stereogeniccenter, are reported. Reactions are promoted in the presence of 4 mol % of a readily available amino acid-based phosphine and 2 mol % (CuOTf).C6H6. Cu-catalyzed reactions proceed efficiently in up to 98% ee
Highly Substituted Enantioenriched Cyclopentane Derivatives by Palladium-Catalyzed [3 + 2] Trimethylenemethane Cycloadditions with Disubstituted Nitroalkenes
作者:Barry M. Trost、Dustin A. Bringley、B. Michael O’Keefe
DOI:10.1021/ol402487s
日期:2013.11.15
β,β-Disubstituted nitroalkenes readily undergo palladium-catalyzed [3 + 2] cycloaddition with trimethylenemethane to generate nitrocyclopentanes in excellent yield and enantioselectivity. The reaction provides access to heavily substituted cyclopentanes containing up to three contiguous stereocenters, and the products may be converted to both cyclopentylamines and cyclopentenones. A rare dependence
Method for producing an optically active nitro compound
申请人:Carreira M. Erick
公开号:US20070037976A1
公开(公告)日:2007-02-15
An optically active nitro compound having two hydrogen atoms on its α-cabon atom and having β-asymmetric carbon atom can be produced by making α, β-unsaturated nitroolefin having a hydrogen atom on its α-cabon atom react with at least two organosilicon compounds having at lest one silicon-hydrogen bond in the molecule in the presence of an asymmetric copper complex, or react with an organosilicon compound having at least one silicon-hydrogen bond in the molecule in the presence of an asymmetric copper complex and water.
The development of a chiral-at-metal iridium(III) complex for the highly efficient catalytic asymmetric transfer hydrogenation of beta,beta'-disubstituted nitroalkenes is reported. Catalysis by this inert, rigid metal complex does not involve any direct metal coordination but operates exclusively through weak interactions with functional groups properly arranged in the ligand sphere of the iridium complex. Although the iridium complex relies only on the formation of three hydrogen bonds, it exceeds the performance of most organocatalysts with respect to enantiomeric excess (up to 99% ee) and catalyst loading (down to 0.1 mol %). This work hints at an advantage of structurally complicated rigid scaffolds for non-covalent catalysis, which especially relies on conformationally constrained cooperative interactions between the catalyst and substrates.
Hydrogen bond-mediated organocatalytic enantioselective reduction of nitroalkenes in deep eutectic solvents