Palladium-Catalyzed Construction of Heteroatom-Containing π-Conjugated Systems by Intramolecular Oxidative C-H/C-H Coupling Reaction

Synthesis of heteroatom-containing ladder-type -conjugated molecules was successfully achieved via a palladium-catalyzed intramolecular oxidative CH/CH cross-coupling reaction. This reaction provides a variety of -conjugated molecules bearing heteroatoms, such as nitrogen, oxygen, phosphorus, and sulfur atoms, and a carbonyl group. The -conjugated molecules were synthesized efficiently, even in gram scale, and larger -conjugated molecules were also obtained by a double CH/CH cross-coupling reaction and successive oxidative cycloaromatization.