The catalyst decomposition in homogeneously catalyzed reactions is a very important factor that has been studied for the oligomerization of n-butenes in a system of two liquid phases. A highly active catalyst [NiCl 2 (PMe 3 ) 2 ] was investigated with an emphasis on the long-term catalyst activity using N-methylpyrrole as a buffer. The recycling experiments indicated that this catalyst is viable for five runs. Furthermore, introducing aluminum chloride or an ionic liquid in small concentrations led to increased stability, though fine adjustments were necessary to arrive at optimal results.
The oligomerization of n-butenes in a two-phase catalyst system consisting of a Lewis acidic ionic liquid (IL) and a nonpolar phase is described. A highly active catalyst system with NiCl 2 (PMe 3 ) 2 was investigated, resulting in 91 % dimers with N-methylpyrrole as a buffer. The reaction was found to be dependent on the molar ratio of the IL to the catalyst. Additionally, the influence of the Lewis acid was investigated and AlCl 3 was determined as the most suitable for activating the nickel complex. The concentration of AlCl 3 played an important role in achieving high catalyst activity and dimer selectivity. Several reactions with different pyrrole derivatives demonstrated that the use of a buffer with low steric hindrance was also important with regard to increased dimer selectivity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.