Organopromoted direct synthesis of 6-iodo-3-methylthioimidazo[1,2-a]pyridines via convergent integration of three self-sorting domino sequences

An NH2CN-promoted convergent integration of three self-sorting domino sequences is described for the construction of 6-iodo-3-methylthioimidazo[1,2-a] pyridines from aryl methyl ketones and 2-aminopyridines. This strategy allows the construction of an imidazo[1,2-a] pyridine ring along with methylthiolation at C-3 and iodination at C-6. Preliminary mechanistic studies indicate that this process terminates at the iodination stage without Kornblum oxidation in the presence of I-2 and DMSO.