A titanium(III)-catalyzed radical cyclization to unprotected 3-aminoindoles, 3-aminopyrroles, or 3-iminoindolines is reported. The reaction is non-hazardous, scalable, and allows facile isolation of the free products by extraction. The method is demonstrated on a large substrate scope and it further allows the direct installation of various nitrogen protecting groups or the synthesis of building blocks
报道了
钛(III)催化的自由基环化成未保护的3-
氨基
吲哚,3-
氨基
吡咯或3-亚
氨基二氢
吲哚。该反应是无害的,可扩展的,并且允许通过萃取容易地分离游离产物。该方法在较大的底物范围内得到了证明,它还允许直接安装各种氮保护基团或以单一顺序合成肽
化学的基础材料。熔融双
吲哚可直接从环化产物中获得。