Metal and acid-free visible light-induced Friedel-Crafts C3-alkylation reactions of indole derivatives were developed using N,N-dimethylanilines as the carbon source. A cheap and readily available organic dye, Rose Bengal, was applied as the photocatalyst. This environmentally friendly transformation afforded C3-alkylated indoles in moderate to good yields under mild conditions.

中文翻译：

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无金属和无酸的可见光介导的吲哚与苯胺的Friedel-Crafts烷基化反应

以N，N-二甲基苯胺为碳源，开发了无金属和无酸的可见光诱导的吲哚衍生物的C3-烷基化反应。一种廉价且容易获得的有机染料玫瑰红被用作光催化剂。这种环境友好的转化在温和的条件下以中等至良好的收率提供了C3-烷基化的吲哚。