Iron(II)-catalyzed denitration reaction: Synthesis of 3-methyl-2- arylimidazo[1,2-a]pyridine derivatives from aminopyridines and 2-methylnitroolefins

摘要

A variety of ways to synthesize imidazo[1,2-a]pyridines have been reported and many approaches are devoted to the functionalization of imidazo[1,2-a] pyridines. However, the use of a denitration reaction in the synthesis of imidazo[1,2-a]pyridines has not been reported. We report here the iron-catalyzed synthesis of 3-methyl-2-arylimidazo [1,2-a] pyridine derivatives from aminopyridines and 2-methyl-nitroolefins. The procedure, using FeCl_2 as catalyst, is simple and inexpensive. Various functional groups are tolerated and provide the products in good yields.