Synthesis of functionalized 2-aryl-4-(indol-3-yl)-4H-chromenes via iodine-catalyzed domino Michael addition-intramolecular cyclization reaction.

An efficient synthesis of novel functionalized 2-aryl-4-(indol-3-yl)-4H-chromenes has been developed, in the presence of a catalytic amount of iodine, from easily available starting materials, 2-hydroxychalcone derivatives. Indole, substituted indoles and 7-azaindole are suitable for this transformation. The possible domino Michael addition-intramolecular cyclization reaction mechanism is proposed.