We report herein a synthesis of 5,6‐diarylbenzo[a]carbazoles by a sequence of 6π‐electrocyclization followed by β‐elimination. The highly functionalized 2,3‐disubstituted indoles used for this cycloaromatization process are prepared by Pd‐catalyzed cyclizative cross‐coupling of ortho‐alkynylanilines with ortho‐alkynylbenzamides. The combination of these two reactions allows us to develop a facile synthesis of benzo[a]carbazoles directly from two easily accessible internal alkynes without isolation of the indole intermediates.

中文翻译：

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可见光诱导的环芳烃化合成苯并[a]咔唑

我们在此报告5,6- diarylbenzo [的合成一个通过为6的序列]咔唑π接着-electrocyclization β在剔除。用于该芳环芳构化过程的高度官能化的2,3-二取代的吲哚是通过Pd催化邻炔基苯胺与邻炔基苯甲酰胺的环化交叉偶联而制得的。这两个反应的结合使我们能够直接从两个易于接近的内部炔烃中轻松合成苯并[ a ]咔唑，而无需分离吲哚中间体。