In this short review, the direct intermolecular cross-coupling reactions of heteroarenes with aryl (pseudo)halides catalyzed by transition metals via C-H bond cleavage in recent years are described. The fundamental emphasis has been given to the synthetic aspects of different intermolecular direct cross-coupling reaction. Much attention is drawn to the palladium-catalyzed arylation reactions due to their important utility at present. Meanwhile, the procedures employed other transition metals are also presented.
Keywords: Aryl (pseudo)halides, C-H activation/functionalization, direct arylation, heteroarenes, transition metals, pallidium complexes, nongenotoxicity, thiazole arylation, oxazole ring system, electron rich