Tandem Michael Addition–Ring Transformation Reactions of 3-Hydroxyoxindoles/3-Aminooxindoles with Olefinic Azlactones: Direct Access to Structurally Diverse Spirocyclic Oxindoles
作者:Bao-Dong Cui、Jian Zuo、Jian-Qiang Zhao、Ming-Qiang Zhou、Zhi-Jun Wu、Xiao-Mei Zhang、Wei-Cheng Yuan
DOI:10.1021/jo500432c
日期:2014.6.6
An efficient method for the direct construction of two classes of spirocyclic oxindoles by the reactions of 3-hydroxyoxindoles/3-aminooxindoles and (Z)-olefinic azlactones through a tandem Michael addition-ring transformation process has been developed. With DBU as the catalyst, a range of spiro-butyrolactoneoxindoles and spiro-butyrolactamoxindoles, containing an oxygen or a nitrogen heteroatom, respectively, in the spiro stereocenter, were smoothly obtained with good to excellent diastereoselectivities in high yields.