Palladium/Imidazolium salt as a versatile catalyst for sequential coupling reactions of aryl dihalides to unsymmetrically substituted arenes

A simple method for one-pot sequential Heck/Suzuki coupling reactions of a range of substituted aryl dihalides has been described. The Pd(OAc)2/imidazolium system catalyzed double coupling reactions proceed without isolation of the intermediates giving unsymmetrically polysubstituted biphenyls in good to excellent yields. Further couplings of the resultant products bearing additional C–Cl bonds with substituted arylboronic acids or amines lead to unsymmetrical terphenyls and aminobiphenyl derivatives.