title: Rapid synthesis of 3-amino-imidazopyridines by a microwave-assisted four-component coupling in one pot.
abstract: The rapid and efficient synthesis of various 2,6-disubstituted-3-amino-imidazopyridines using a microwave-assisted one-pot cyclization/Suzuki coupling approach is described. The utility of a 2-aminopyridine-5-boronic acid pinacol ester as a robust and versatile building block for the synthesis of diverse compound libraries is emphasized. The boronate functional group is remarkably tolerant to the Lewis acid catalyzed cyclizations, and the subsequent Pd(0)-catalyzed Suzuki coupling reactions proceed cleanly in the presence of magnesium salts. This work highlights the vast potential of microwave-assisted, metal-catalyzed, multicomponent reactions.
authors.affiliation: Department of Medicinal Chemistry, Amgen Inc., One Kendall Square, Building 1000, Cambridge, Massachusetts 02139, USA. erin.dimauro@amgen.com
authors.forename: Erin F
authors.initials: EF
authors.lastname: Dimauro
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Kennedy
mesh_terms: D001897:Boronic Acids / Q000737:chemistry; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D004952:Esters / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry; D008872:Microwaves; D008956:Models, Chemical; D010165:Palladium / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry*; D012492:Salts / Q000737:chemistry
chemical_list: D001897:Boronic Acids; D004952:Esters; D007093:Imidazoles; D011725:Pyridines; D012492:Salts; D010165:Palladium; D008274:Magnesium