Department of Chemistry, Dartmouth College, Hanover, NH, 03755, USA.
Angew Chem Int Ed Engl. 2017 Mar 27;56(14):3951-3955. doi: 10.1002/anie.201612311. Epub 2017 Mar 3.
We report an unprecedented transition metal-free coupling of indoles with aryl halides. The reaction is promoted by KOtBu and is regioselective for C3 over N. The use of degassed solvents devoid of oxygen is necessary for the success of the transformation. Preliminary studies implicate a hybrid mechanism that involves both aryne intermediates and non-propagative radical processes. Electron transfer is also a distinct possibility. These conclusions were substantiated by EPR data, isotopic labeling studies, and the use of radical scavengers and electron transfer inhibitors.
我们报告了吲哚与芳基卤化物之间前所未有的过渡金属自由偶联。该反应由 KOtBu 促进，且 C3 位相对于 N 位具有区域选择性。成功转化需要使用脱气、无氧的溶剂。初步研究表明，该反应涉及芳炔中间体和非传播性自由基过程的混合机制。电子转移也是一种可能的情况。这些结论得到了 EPR 数据、同位素标记研究以及自由基清除剂和电子转移抑制剂的使用的证实。
