Simple Br?nsted acid catalyzed C-H functionalization: Efficient access to poly-substituted pyridines

Article abstract of DOI:10.1016/j.tetlet.2016.05.061

An exceptionally simple and environmentally friendly methodology has been developed for directly functionalizing the benzylic C-H bond of the poly-substituted pyridines with aromatic imines. Simple Br?nsted acid catalysts including salicylic acid and TsOH were successfully employed. Different types of poly-substituted pyridines could be efficiently obtained with moderate yields. Traditional ways to such types of pyridines involved the aromatization of the corresponding Hantzsch 1,4-dihydropyridines, while this method greatly simplified the synthetic procedures.