Facile Assembly of 11H-Indolo[3,2-c]quinoline by a Two-Step Protocol Involving a Regioselective 6-endo-Cyclization Promoted by the Hendrickson Reagent

Abstract

An expedient approach was developed to construct the 11H-indolo[3,2-c]quinoline scaffold starting from acyclic alkyne substrates. The five- and six-membered nitrogen-containing rings in the tetracyclic skeleton were elaborated efficiently by gold(III)-catalyzed 5-endo-dig cyclization and Hendrickson reagent promoted regioselective 6-endo cyclization.