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 conjugate addition (ACA) of alkylzinc reagents to trisubstituted nitroalkenes, leading to the formation of nitroalkanes bearing a quaternary carbon stereogenic center, 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
报道了烷基锌试剂与三取代硝基烯烃的催化不对称共轭加成 (ACA) 的第一个例子,导致形成带有季碳立体中心的硝基烷烃。在 4 mol% 的易于获得的基于氨基酸的膦和 2 mol% (CuOTf).C6H6 的存在下促进反应。Cu 催化的反应在高达 98% ee 的情况下有效进行,并且可以使用各种二烷基锌试剂和三取代硝基烯烃进行。我们强调了通过将光学富集的硝基烷烃有效转化为相应的羧酸而获得的产品的合成效用。