Investigation of 1-hexene isomerization and oligomerization catalyzed with β-diketiminato Ni(II) bromide complexes/methylaluminoxane system

Article abstract of DOI:10.1016/j.molcata.2004.12.024

β-Diketiminato Ni(II) bromide complexes were synthesized and used to catalyze isomerization and oligomerization of 1-hexene in the presence of methylaluminoxane (MAO). GC-MS and GC analysis confirmed that the products are mainly hexene isomers and dimer isomers. 3-Hexene isomers, trimers and higher oligomers were not detected. The results were ascribed to the configuration of the β-diketiminato Ni(II) catalyst. The migration of the Ni atom from a secondary or tertiary carbon to another one along the alkyl chain of the Ni-alkyl intermediates is blocked by the coordination wedge of the β-diketiminato ligands. However, the migration of the Ni atom from a primary carbon to the adjacent secondary or tertiary carbon is thermodynamically favored.