Olefin oligomerization by novel catalysts prepared by oxidative addition of carboxylic acids to nickel(0) precursors and modified by phosphine ancillary ligands and organoaluminum compounds

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2001-03, Vol.169 (1), p.79-88
• Main Authors: Carlini, Carlo, Marchionna, Mario, Raspolli Galletti, Anna Maria, Sbrana, Glauco
• Format: Article
• Language: English
• Subjects: 2,3-Dimethylbutenes; 2-Nitrobenzoic acid; C 4–C 12 oligomers; Catalysis; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; Homogeneous nickel catalysts; Organoaluminum co-catalysts; Propylene and ethylene oligomerization; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Tricyclohexylphosphine; Trifluoroacetic acid
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/S1381-1169(01)00040-1

Novel Ziegler–Natta-type catalysts, prepared in situ by oxidative addition of carboxylic acids to bis(cyclooctadiene)nickel(0) [Ni(cod) 2]/phosphine adducts and activated by different organoaluminum compounds, are described. These catalysts resulted very active in olefin oligomerization. When 2-nitrobenzoic acid (NBA), tricyclohexylphosphine (PCy 3) and MAO were employed in combination with Ni(cod) 2 for propylene oligomerization, a regioselectivity to 2,3-dimethylbutenes (DMB) within the C 6 cut very close to 90% was achieved with a high productivity (turnover frequency (TOF) values up to 16,400 h −1). Similar results in terms of regioselectivity to DMB were obtained when trifluoroacetic acid (TFA) was adopted. However, although with a lower productivity, a higher value of overall yield to DMB (62.7%) was achieved. When these catalysts were used for ethylene oligomerization they resulted very active (TOF values up to 65,000 h −1), the nature of the phosphine ligand allowing to strongly affect the chemoselectivity of the process, shifting the oligomeric composition towards specific fractions.