“Zinc-Catalyzed Reactions of Ethenetricarboxylates with
2-(Trimethylsilylethynyl)anilines Leading to Bridged Quinoline Derivatives”
Shoko Yamazaki, Satoshi Morikawa, Kazuya Miyazaki, Masachika Takebayashi
Yuko Yamamoto, Tsumoru Morimoto, Kiyomi Kakiuchi, Yuji Mikata
Org. Lett. 2009, 11,13, 2796-2799.
Zinc Lewis acid-catalyzed cyclization of ethenetricarboxylate derivatives 1 with 2-ethynylanilines has been examined. Reaction of 1,1-diethyl 2-tert-butyl ethenetricarboxylate1b with 2-(trimethylsilylethynyl)aniline substrates in the presence of Zn(OTf)2 gave bridged quinoline derivatives in 43−85% yield. The reaction of 1b with 2′-aminoacetophenone also gave the bridged quinoline derivative in 41% yield. Thermal reaction of bridged quinolines (180−190 °C) afforded indole derivatives in moderate to good yields.