Cobalt-catalyzed vinylation of functionalized aryl halides with vinyl acetates

A new method for the preparation of styrene derivatives is described on the basis of the activation of aryl halides by low-valent cobalt species. A combination of CoII bromide and 2,2′-bipyridine is suitable as catalyst for the cross-coupling reaction of a wide range of aromatic halides (X = Cl, Br, I), mostly bearing sensitive moieties, with vinyl acetates. These reactions proceed under mild conditions in the presence of the appropriate reducing agent to afford α-substituted styrene compounds in satisfactory to high yields.