Selective Trimerization ofα-Olefins with Triazacyclohexane Complexes of Chromium as Catalysts

Abstract

Olefin trimers can be prepared selectively from α‐olefins with n‐alkyl‐substituted triazacyclohexane–CrCl3 complexes as catalysts in the presence of methyaluminoxane (MAO).

Advances in selective ethylene trimerisation – a critical overview

“…Kö hn et al [50] subsequently showed that these triazacyclohexane complexes of Cr(III) were capable of trimerising higher alpha olefins such as propene, 1-hexene and styrene. Up until this time no other trimerisation catalysts were shown to be capable of this transformation with higher olefin substrates.…”

Neutral palladium(II) complexes with P,N Schiff-base ligands: Synthesis, characterization and catalytic oligomerisation of ethylene

“…Reactions carried out beyond 1 min showed a gradual decrease in the catalytic activities. For example, catalyst system 2b/ EtAlCl 2 afforded 7.6, 7.1, 6.2 and 4.2 Â 10 2 g mol À1 Pd h À1 after 1, 5, 15, and 30 min (Table 3, entries 5, 6,7,8) respectively. In addition, increasing the reaction time from 1 to 30 min led to a slight reduction in the amount of C 4 (e.g.…”

Chromium(III) complexes bearing 2-benzoxazolyl-6-arylimino-pyridines: Synthesis and their ethylene reactivity

“…It is well known that heterogeneous catalysts result in multisite active species in olefin polymerization [5][6][7], however, homogeneous catalysts provide the opportunity in understanding the active species and polymerization/oligomerization mechanism which might be helpful in designing advanced catalysts [8][9][10]. On the other hand, chromium catalysts are still being the only practicing catalysts for the on-purpose process for ethylene trimerization or tetramerization [11][12][13][14][15][16][17][18][19]. Therefore it has attracted for designing homogeneous catalysts of chromium complexes through developing multidentate ligands, such as N^N (iminopyrrolide [20,21], b-diketiminate [21][22][23][24][25], bis(phosphoranimine)methanide [26] and bis(imidazole) [27,28]), N^O [29][30][31], P^P or P^N^P [32][33][34][35][36][37][38][39], P^P^P [40], N^P^N [41], S^N^S [34,35,42], N^S^N [43], C^N^C [44], N^N^O [4...…”