Efficient synthesis of carbazoles via PtCl2-catalyzed RT cyclization of 1-(indol-2-yl)-2,3-allenols: scope and mechanism
作者:Wangqing Kong、Chunling Fu、Shengming Ma
DOI:10.1039/c1ob06474f
日期:——
A detailed study on the scope of the efficient PtCl2-catalyzed synthesis of carbazoles from 1-(indol-2-yl)-2,3-allenols is described. Through isotopic labeling experiments, it is confirmed that the reaction proceeds through a unique metal carbene intermediate, which undergoes subsequent highly selective 1,2-hydrogen migration to afford carbazoles. The reaction shows wide scope and allows the introduction of a variety of different substituents at different positions on the carbazole due to the substituent-loading capability of both indole and the allene moiety.
详细研究了1-(吲哚-2-基)-2,3-烯醇在PtCl2催化下高效合成咔唑的反应范围。通过同位素标记实验,证实反应是通过一种独特的金属炔中间体进行的,该中间体随后发生高度选择性的1,2-氢迁移,生成咔唑。该反应范围广泛,由于吲哚和烯基部分都具有负载取代基的能力,因此可以在咔唑的不同位置上引入各种不同的取代基。