Additives boosting the performance of tungsten imido-mediated ethylene dimerization systems for industrial application.

While activation of tungsten bis(imido) complexes [WCl(NAr)(dme)] with EtAlCl affords active, and moderately selective ethylene dimerization catalysts, addition of EtN or OctNCl leads to a doubling in productivity and activity, along with increased selectivity (e.g., >93% C, >99% 1-C). The performance of the resulting tungsten-based catalyst package is competitive with that of Axens' commercialised Ti-based AlphaButol process and exemplifies the wide potential of similar additives in selective oligomerization.