Friedel-Crafts Alkylation of Toluene as a Parallel Reaction in Propylene Dimerization Catalyzed by Nickel β-Diimine Complex/EASC in Homogeneous Phase

Propylene oligomerization was performed using dibromo-bis(N,N'-diphenylpentane-2,4- diimine)nickel(II) complex as catalytic precursor combined with ethyl aluminum sesquichloride (Al₂Et₃Cl₃, EASC) as co-catalyst. At 10 ºC, using toluene as solvent, high turnover frequencies (up to 57,000 h^–1) with high selectivities to C₆ products (up to > 99%) and moderate linear C₆ selectivity (up to 29%) were obtained. Under our reaction conditions propylene reacted with toluene through Friedel-Crafts reaction. Increasing the concentration of catalyst precursor keeping the nickel complex/co-catalyst ratio constant increased the selectivity of the oligomerization products vs. Friedel-Craft products.

nickel; ß-diimine ligands; propylene oligomerization; Friedel-Crafts alkylation