A Cu(ii)-promoted tandem decarboxylative halogenation and oxidative diamination reaction of 2-aminopyridines with alkynoic acids for the synthesis of 2-haloimidazo[1,2-a]pyridines.

A copper-promoted cascade decarboxylative halogenation and oxidative diamination reaction sequence of 2-aminopyridines with alkynoic acids has been developed for the synthesis of 2-haloimidazo[1,2-a]pyridines. In this reaction, two C-N bonds and one C-halogen bond are formed in one pot, generating the desired products in good yields. This is the first report on the synthesis of 2-haloimidazo[1,2-a]pyridine derivatives from alkynoic acids.