Synthesis of 2‐Methylindoles through Ruthenium(II)‐Catalyzed Reaction of Aniline Derivatives with Allylamines

Abstract The ruthenium(II)‐catalyzed reaction of aniline derivatives with allylamines was carried out, affording 2‐methylindoles via C−H/C−N bond activation. 4,5‐Dimethyl pyrimidin‐2‐yl group attached on the nitrogen atom of anilines is the most effective directing group and N ‐allyl‐4‐fluoro‐ N ‐methylaniline is the optimal allylamine. The cyclization products were obtained in 16% to 96% yields. The method does not require external oxidant. A possible mechanism is proposed. magnified image