An efficient and facile synthesis of 2,3′-biindoles through Co(III)-catalyzed direct C–H coupling of N-pyrimidinylindoles with 3-diazoindolin-2-imines is reported. This method provided 2,3′-biindoles under mild reaction conditions and in moderate to excellent yields. The reaction tolerated a number of functional groups and could be scaled up with practical usage.

中文翻译：

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Co（III）催化3-重氮吲哚-2-亚胺与1-pyrimidinylinlindoles之间的反应，合成2,3'-双吲哚

据报道，通过Co（III）催化的N-嘧啶基林多烯与3-重氮吲哚-2-亚胺的直接C–H偶联，可以有效，轻松地合成2,3'-双吲哚。该方法在温和的反应条件下以中等至极好的收率提供了2,3'-联吲哚。该反应容许许多官能团，并且可以通过实际使用扩大规模。