2014-2013
首页  科学研究  发表论文  2014-2013

Highly Efficient and Stereocontrolled Construction of 3,3'-Pyrrolidonyl Spirooxindoles via Organocatalytic Domino Michael/Cyclization Reaction(Org. Lett., 2013, 15, 1246–1249)

Graphic Abstract

  

We have developed a highly efficient and stereocontrolled method for the construction of densely functionalized 3,3'-pyrrolidonyl spirooxindole derivatives with quinine as catalyst under mild reaction conditions. The reactions are accomplished via domino Michael addition/cyclization reaction between 3-isothiocyanato oxindoles and 3-methyl-4-nitro-5-alkenyl-isoxazoles for delivering a wide range of structurally diverse 3,3'-thiopyrrolidonyl spirooxindoles bearing three contiguous stereogenic centers. Most importantly, the process is significantly characterized by high reactivity, low catalyst loading (1 mol %), as well as excellent diastereo- and enantioselectivity (up to >99:1 d.r., 98% ee, and 97% yield). The utilities of the protocol have been demonstrated by the gram scale reaction and the versatile conversion of the cycloadduct into other 3,3'-spirocyclic oxindoles. The further studies into exploring the reaction between 3-isothiocyanato oxindoles and various other reactants for the construction of diversely structured spirocyclic oxindoles are in progress