Novel synthetic strategy of carbolines via palladium-catalyzed amination and arylation reaction

Four parent carbolines and the corresponding 5- or 9-methylsulfonyl derivatives were synthesized by the palladium-catalyzed intramolecular arylation reaction of ortho-bromo-substituted anilinopyridines which were prepared by the palladium-catalyzed arnination reaction of iodobenzenes with aminopyridines. Carbazole and its 9-methylsulfonyl derivative were also synthesized by the same method.