Enantioselective synthesis of fused dihydropyranones via squaramide-catalyzed Michael addition/lactonization cascade reaction
作者:Jialing Xian、Lin Chen、Ling Ye、Yin Sun、Zhichuan Shi、Zhigang Zhao、Xuefeng Li
DOI:10.1016/j.tet.2019.03.007
日期:2019.4
A highly enantioselective (49–99% ee) Michael addition/lactonization cascade process has been developed to construct 3,4-dihydropyran-2-one in the presence of a bifunctional squaramide. Various α,β-unsaturated N-acyl heterocycles were well tolerated and afforded 3,4-dihydropyran-2-ones in moderate to excellent isolated yields (50–99%). Both cyclic and acyclic β-diketones functioned as appropriate donors
已经开发了一种高度对映选择性(49-99%ee)的迈克尔加成/内酯化级联方法,可在双功能方酰胺存在下构建3,4-二氢吡喃-2-酮。各种α,β-不饱和N-酰基杂环具有良好的耐受性,并以中等至极好的分离产率(50-99%)提供了3,4-二氢吡喃-2-酮。环状和非环状的β-二酮都可以作为合适的供体。所得的3,4-二氢吡喃-2-酮可容易地转化为草并cali醛。