Synthesis of 2-substituted indoles by palladium-catalyzed heteroannulation with Pd–NaY zeolite catalysts

Various 2-substituted indoles were prepared by heteroannulation of o-iodoanilines and terminal alkynes in a one-pot reaction with a Pd(II)–NaY zeolite catalyst. The product formation largely depended on the solvent, base, and reaction temperature. The recycled catalyst showed good reusability in the heteroannulation reaction.