Regioselective Direct C‑3 Arylation of Imidazo[1,2‑<i>a</i>]pyridines with Aryl Tosylates and Mesylates Promoted by Palladium–Phosphine Complexes

Abstract

Direct C-3 arylation of imidazo­[1,2-<i>a</i>]­pyridines with aryl tosylates and mesylates has been accomplished by employing palladium­(II) acetate associated with SPhos (2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl) or <b>L1</b> (2-(2-(diiso­propyl­phos­phino)­phenyl)-1-methyl-1<i>H</i>-indole). This catalyst system can be applied to a wide range of aryl sulfonates and shows excellent C-3 regioselectivity of imidazo­[1,2-<i>a</i>]­pyridine. These results represent the first examples of using tosylate- and mesylate-functionalized arenes as the electrophile partners for this regioselective direct arylation