Development of a general process for the synthesis of highly substituted imidazoles
Several highly substituted imidazoles have been under investigation at GlaxoSmithKline as potential therapies for the treatment of rheumatoid arthritis and have spawned the need for a general synthetic method for their preparation on a multikilogram scale. We describe herein the optimization of a general method for the preparation of aryl-substituted TosMIC reagents and the ease with which they undergo [3+2] cycloadditions with a host of imines, prepared in situ, to generate densely functionalized imidazoles with various substitution patterns in a completely regioselective manner.