Selective dimerisation of 1-hexene mediated by aluminium alkyl chloride-activated tungsten imido complexes

Dyer, Philip W.; Hanton, Martin J.; Messinis, Antonis M.

Abstract

The selective dimerisation of 1-hexene to dodecenes was accomplished using catalysts generated from a tungsten mono- [WCl4(NR)(thf)] or bis- [WCl2(NR)2(dme)] imido complex following activation with EtAlCl2. These catalytic systems achieve 1-hexene dimerisation with productivities of up to 3757 (mol C6)(mol W)–1 and selectivities towards the dimer fraction of 88–99 wt%. Tungsten pro-catalysts bearing imido ligands with electron donating groups give high productivity and good selectivity towards the desired methyl-branched dimers. Contrastingly, complexes with electron withdrawing imido motifs are inactive for oligomerisation, instead mediating 1-hexene isomerisation. The efficacy of different aluminium-containing activators is described, with EtAlCl2 giving the best catalytic performance at a low W:Al ratio of 8 – 20. Addition of catalyst modifiers (e.g. Oct4NCl and Et3N) is found to significantly improve the catalytic performance of the alkyl aluminium-activated olefin oligomerisation systems.

Citation

Dyer, P. W., Hanton, M. J., & Messinis, A. M. (online). Selective dimerisation of 1-hexene mediated by aluminium alkyl chloride-activated tungsten imido complexes. Catalysis Science & Technology, https://doi.org/10.1039/d0cy01863e

• Journal Article Type: Article
• Acceptance Date: Nov 26, 2020
• Online Publication Date: Nov 27, 2020
• Deposit Date: Dec 7, 2020
• Publicly Available Date: Nov 26, 2021
• Journal: Catalysis Science & Technology
• Print ISSN: 2044-4753
• Electronic ISSN: 2044-4761
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1039/d0cy01863e
• Public URL: https://durham-repository.worktribe.com/output/1255928