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

Abstract

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.