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

Abstract

While activation of tungsten bis(imido) complexes [WCl₂(NAr)₂(dme)] with EtAlCl₂ affords active, and moderately selective ethylene dimerization catalysts, addition of Et₃N or Oct₄NCl leads to a doubling in productivity and activity, along with increased selectivity (e.g., >93% C₄, >99% 1-C₄). 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.