Iron-Catalyzed 1,5-Enyne Cycloisomerization via 5-Endo-Dig Cyclization for the Synthesis of 3‑(Inden-1-yl)indole Derivatives

An Fe­(OTf)3-catalyzed 1,5-enyne cycloisomerization via 5-endo-dig cyclization is described for the synthesis of 3-(1-indenyl)­indole derivatives. Since a variety of 1,5-enynes are readily accessible via Heck–Suzuki coupling, this strategy provides a rapid and easy access to a wide range of highly substituted 3-(1-indenyl)­indoles in good yields.