Palladium-Catalyzed Ethylene/Methyl Acrylate Cooligomerization: Effect of a New Nonsymmetric α-Diimine

Authors

  • Angelo Meduri,

    1. Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste (Italy), Fax: (+39) 0405583903
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  • Dr. Tiziano Montini,

    1. Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste (Italy), Fax: (+39) 0405583903
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  • Prof. Dr. Fabio Ragaini,

    1. Department of Chemistry, University of Milano, Via C. Golgi 19, 20133 Milano (Italy)
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  • Prof. Dr. Paolo Fornasiero,

    1. Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste (Italy), Fax: (+39) 0405583903
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  • Prof. Ennio Zangrando,

    1. Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste (Italy), Fax: (+39) 0405583903
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  • Dr. Barbara Milani

    Corresponding author
    1. Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste (Italy), Fax: (+39) 0405583903
    • Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste (Italy), Fax: (+39) 0405583903
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Abstract

A new nonsymmetric bis(aryl-imino)acenaphthene (Ar-BIAN) ligand, featured by a subtle steric and electronic unbalance of the N-donor atoms, is reported. With the new ligand and the corresponding symmetrically substituted derivatives, both neutral and monocationic Pd[BOND]CH3 compounds have been synthesized and characterized. The series of the monocationic complexes [Pd(CH3)(L)(Ar-BIAN)][PF6] (L=CH3CN, dmso) has been extended to dimethyl sulfoxide derivatives. The monocationic complexes are tested as precatalysts for the ethylene/methyl acrylate cooligomerization under mild reaction conditions of temperature and ethylene pressure. The catalytic product is a mixture of ethylene/acrylate cooligomers and higher alkenes. The catalysts containing the new nonsymmetric ligand are found to be more productive than those with the symmetric Ar-BIANs. The Pd–dmso catalysts are more productive and show a longer lifetime than their Pd–NCCH3 counterparts.

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