for the coupling of aryl halides with aryl grignards, nickel chloride in tetrahydrofuran (thf) is also a good catalyst. additionally, an effective catalyst for the couplings of alkyl halides is dilithium tetrachlorocuprate (li2cucl4), prepared by mixing lithium chloride (licl) and copper(ii) chloride (cucl2) in thf. the kumada-corriu coupling gives access to [substituted] styrenes.