Selective Synthesis of 5,6-Dihydroindolo[1,2-<i>a</i>]quinoxalines and 6,7-Dihydroindolo[2,3-<i>c</i>]quinolines by Orthogonal Copper and Palladium Catalysis
作者:Lei Zhang、Fei Zhao、Mingyue Zheng、Yun Zhai、Jiang Wang、Hong Liu
DOI:10.1002/ejoc.201300667
日期:2013.9
heterocycles have been prepared in two steps from readily accessible starting materials. From the same set of Ugi adducts 5, 5,6-dihydroindolo[1,2-a]quinoxalines 6 were rapidly generated in excellent yields by a copper-catalyzed N–H arylation pathway, whereas 6,7-dihydroindolo[2,3-c]quinolones 7 were obtained by palladium-catalyzed C–H arylations in good yields without the protection of the indole N1 moiety
结合 Ugi 四组分反应,两个重要的吲哚稠合杂环已从易于获得的起始材料中分两步制备。从同一组 Ugi 加合物 5 中,5,6-二氢吲哚[1,2-a]喹喔啉 6 通过铜催化的 N-H 芳基化途径以极好的收率快速生成,而 6,7-二氢吲哚[2,3 -c] 喹诺酮类化合物 7 通过钯催化的 C-H 芳基化以良好的产率获得,而没有吲哚 N1 部分的保护。微波加热用于加速这些在受控反应条件下进行的分子内 C-N 和 C-C 键形成反应。