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Synthesis of Fused Carbazoles by Gold-Catalyzed Tricyclization of Conjugated Diynes via Rearrangement of an N-Propargyl Group

Research paper by Masamitsu Taguchi, Yusuke Tokimizu, Shinya Oishi, Nobutaka Fujii, Hiroaki Ohno

Indexed on: 10 Dec '15Published on: 09 Dec '15Published in: Organic Letters



Abstract

Various N-propargylanilines bearing a conjugated diyne moiety at the 2-position were converted to tetracyclic fused carbazoles by treatment with a homogeneous gold(I) catalyst. This cascade reaction proceeds through indole formation with concomitant rearrangement of the N-propargyl group, intramolecular nucleophilic addition toward the resulting allene moiety, and subsequent hydroalkenylation. This transformation enables a one-pot synthesis of fused carbazoles from readily accessible substrates with 100% atom economy.

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