Ylide Nickel Complexes Novel Polymerization Catalysts

Ylide Nickel Complexes Novel Polymerization Catalysts 

Obviously, ylide complexes such as 1, in which the ylide ligand is coordinated via the ylidic anion center to a suitable transition metal, are of interest concerning their properties as polymerization catalysts in comparison to commonly used ligands such as phosphanes, which differ significantly in the energetic availability of the ligand lone pair electrons as well as in the ligand donor/acceptor ratio. This chapter reviews research results in this area, obtained in the Central Research Laboratories of Bayer in Leverkusen. 

The reaction of the stabilized ylide benzoylmethylene-triphenylphosphorane with Ni(0) in the presence of triphenylphosphane leads to the oligomerization catalyst 2, which catalyzes the reaction of 6000 moles of ethylene per mole of complex at 50 bar and 50°C. The catalyst 2 is a model system for the Shell Higher Olefin Process (SHOP) for the production of liquid a-olefms of high linearity, which has been studied in detail by Keim and coworkers at the RWTH Aachen [9 c and literature, reviewed in 8]. 

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Ylide Nickel Complexes Novel Polymerization Catalysts... 

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