The synthesis of symmetrical (2-indolyl)ethynes and reduced congeners<i>via</i>palladium-catalyzed couplings of 2-bromoindole precursors
作者:Anthony D. Sercel、H. D. Hollis Showalter
DOI:10.1002/jhet.5570430326
日期:2006.5
two-carbon linker followed by desilylation and further coupling with starting 2-bromoindole. A second shorter and more efficient route engaged the starting 2-bromoindole in a double Stille coupling with bis(tributylstannyl) acetylene or (E)-1,2-bis(tributylstannyl)ethylene to provide desired homodimers in one step. Subsequent transformations of dimeric intermediates led to target acids 7a-c and derived amides
从一系列在3-位被醛,酯或酰胺官能团活化的2-溴-1-甲基吲哚前体(1b-e)开始,已开发出两种合成2,2'-双(吲哚基)的方法乙炔和还原的同类物通过钯(0)或钯(II)催化的偶联。第一种方法利用(三甲基甲硅烷基)乙炔的Sonogashira偶联引入二碳连接基,然后进行甲硅烷基化,然后进一步与起始2-溴吲哚偶联。第二种更短,更有效的途径是使起始2-溴吲哚与双(三丁基锡烷基)乙炔或(E)-1,2-双(三丁基锡烷基)乙烯在一个步骤中提供所需的均二聚体。二聚体中间体的后续转化导致目标酸7a-c以及衍生的酰胺8a-c和9。当针对一组酪氨酸激酶进行测试时,发现每种目标化合物均无活性。