Direct cobalt-catalyzed conjugate addition of functionalized aryl halides and triflates: A new strategy for the conjugate addition onto methyl vinyl ketone

An efficient cobalt-catalyzed method for the direct conjugate addition of functionalized aryl halides or triflates onto methyl vinyl ketone is described. The experimentally simple procedure relies on the use of a catalytic system consisting of CoBr₂(Bpy) and zinc and does not require the preformation of a stoichiometric organometallic species. The approach described herein displays considerable functional-group compatibility at good to excellent yields.