Nickel(0)/imidazolium carbene catalyst system for efficient cross-coupling of aryl bromides and chlorides with organomanganese reagents

N,N'-Bis(2,6-diisopropylphenyl)imidazolium chloride associated with nickel(II) acetylacetonate (3-5 mol%) was used as catalyst to efficiently cross-couple functionalized aryl bromides with organomanganese reagents. The reactions were performed between 0 degrees C and room temperature, giving unsymmetrical biaryls in 0.25 to 24h with 52 to 100% yields for isolated materials. Aryl chlorides showed slightly diminished reactivity in Ni/2 IPr-catalyzed cross-couplings and good yields could only be attained with activated or neutral substrates.