National Engineering Research Center of Chiral Drugs, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China.
J Org Chem. 2013 Sep 6;78(17):8833-9. doi: 10.1021/jo401154b. Epub 2013 Aug 21.
An enantioselective synthesis of quaternary 3-aminooxindoles with 3-monosubstituted 3-aminooxindoles as nucleophiles is first presented. A Michael addition reaction of 3-monosubstituted 3-aminooxindoles to nitroolefins has been developed with a bifunctional thiourea-tertiary amine as a catalyst to afford a range of 3,3-disubstituted oxindoles bearing adjacent quaternary-tertiary centers in good results (up to 98% yield, >99:1 dr, and 92% ee). We also demonstrate the potential synthetic utility of this methodology by a transformation of the product into a spirocyclic oxindole compound.
本文首次报道了一种通过手性亚砜-叔胺双功能催化剂实现的 3-单取代 3-氨基氧化吲哚作为亲核试剂的对映选择性合成季碳 3-氨基氧化吲哚的方法。该方法通过迈克尔加成反应，以硝基烯烃作为迈克尔受体，以 3-单取代 3-氨基氧化吲哚作为亲核试剂，在温和的反应条件下以高对映选择性（高达 98%的产率、>99:1 的 dr 值和 92%的 ee 值）得到一系列含有相邻季碳-叔碳中心的 3,3-二取代氧化吲哚类化合物。我们还通过将产物转化为螺环氧化吲哚化合物，展示了该方法的潜在合成应用价值。
