Abstract : Herein, we report that palladium-catalyzed C-H bond activation can overcome some of the challenges in the preparation of pi-extended aromatics containing one or two heteroelements, which are important structures in organic materials science. The sequential palladium-catalyzed intermolecular direct C5-arylation of heteroarenes by aryl bromides, followed by bromination of the heteroarene unit with N-bromosuccinimide, and finally palladium-catalyzed intramolecular direct arylation allowed the synthesis of the desired phenanthro[9,10-b]thiophenes, phenanthro[9,10-b]furans, phenanthro[9,10-b]thiazoles, acenaphtho[1,2-d]thiophenes, and acenaphtho[1,2-d]thiazoles in only three steps.
