An efficient and recyclable iron(III)-containing imidazolium salt catalyst for cross-coupling of aryl Grignard reagents with alkyl halides

1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride, DIPrim]Cl, was used to produce a novel iron(III)-containing imidazolium salt DIPrim]FeCl 4 ], which included a N,N-diarylimidazolium cation (R = 2,6-diisopropylphenyl), DIPrim] + , and tetrachloroferrate(III) anion, FeCl 4 ]. This compound was an effective and easy-to-use catalyst for the cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides bearing -hydrogens. After simply decanting the cross-coupling product in the ether layer, DIPrim]FeCl 4 ] could be reused in at least four successive runs without significant loss of catalytic activity.