Cr Complexes of Nitrogen Donor Ligands for Olefin Oligomerisation and Polymerisation

McGuinness, David S.

doi:10.1007/978-90-481-3815-9_1

Cited by 3 publications

(2 citation statements)

References 91 publications

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“…is one of the important key reactions in chemical industry . The subject concerning design of the efficient (highly active and selective) catalysts thus attract considerable attention; − examples for ethylene oligomerization especially using nickel, , iron complex catalysts, or ethylene trimerization especially using chromium − or titanium complex catalysts have been well-known. Two reaction mechanisms via metal–hydride (or metal–alkyl) or metallacycle intermediate have been postulated in the ethylene oligomerization; the latter mechanism can be especially considered for the selective trimerization (and tetramerization) affording 1-hexane (and 1-octene) with high selectivity.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of (Adamantylimido)vanadium(V) Dimethyl Complex Containing (2-Anilidomethyl)pyridine Ligand and Selected Reactions: Exploring the Oxidation State of the Catalytically Active Species in Ethylene Dimerization

et al. 2017

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Me 2 C 6 H 3 ], prepared from V(NAd)Cl 2 (L) (1) by reaction with LiMe (2.0 equiv), exhibited remarkable catalytic activities for ethylene dimerization in the presence of MAO affording 1-butene with high selectivity [TOF = 1 120 000−1 530 000 h −1 (311−425 s −1 ), C 4 ′ = 97.1−98.4%], and the catalyst performances (activity, selectivity) were similar to those by the dichloride analogue (1) under the same conditions. The dimethyl complex (2a) reacted with 1.0 equiv of R′OH to yield the mono alkoxide complexes, V(NAd)Me(OR′)(L) [R′ = OC(CF 3 ) 3 (3a), OC(CH 3 )(CF 3 ) 2 (3b), OC(CH 3 ) 3 (3c)], and structures of these complexes (3a−c) and 2a were determined by Xray crystallography. Reactions of 2a with [Ph 3 C][B(C 6 F 5 ) 4 ] in Et 2 O and 3c with B(C 6 F 5 ) 3 in THF afforded the corresponding cationic complexes confirmed by NMR spectra. Both NMR and V K-edge XANES analysis of the toluene or toluene-d 8 solution of 1 and 2a did not show any significant changes in the oxidation state upon addition of MAO, Me 2 AlCl, or Et 2 AlCl (10 equiv). Resonances ascribed to formation of the other vanadium(V) species were observed in the 51 V NMR spectra, and no significant differences in the XANES spectra (V−K pre-edge peaks and edge) were observed from 1 or 2a upon addition of Al cocatalyst. Taking into account these results and others, it is thus suggested that cationic vanadium(V) alkyl/hydride species play a role in this catalysis.

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Section: Introductionmentioning

confidence: 99%

Synthesis of (Adamantylimido)vanadium(V) Dimethyl Complex Containing (2-Anilidomethyl)pyridine Ligand and Selected Reactions: Exploring the Oxidation State of the Catalytically Active Species in Ethylene Dimerization

et al. 2017

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“…Concurrently a large expansion in the number of catalytic applications employing β-diketiminate transition-metal complexes is in progress. In particular, the fields of polymerization, oxidation, olefin metathesis, hydrogenation, , and hydroamination have witnessed significant developments. Recently we described the synthesis and characterization of the first β-diketiminatoruthenium complexes supported by neutral η 6 -arene ligands .…”

Section: Introductionmentioning

confidence: 99%

Modulating the Steric, Electronic, and Catalytic Properties of Cp* Ruthenium Half-Sandwich Complexes with β-Diketiminato Ligands

et al. 2011

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Five different types of β-diketiminate ligands, bearing electrondonating to strongly electron-withdrawing substituents, were synthesized and used in the synthesis of Cp* ruthenium complexes (Cp* = η 5 -C 5 Me 5 ). One series consists of complexes with a covalent Ru III −Cl bond, and the other series features a reduced Ru II center, where the chloride is abstracted by treatment of the corresponding Ru III compounds with Zn or Mg. All compounds were characterized by single-crystal X-ray diffraction, UV−visible spectroscopy, and cyclic voltammetry. In the case of Ru II complexes, solution NMR techniques provided key information regarding the electronic and structural differences induced by the different β-diketiminate ligands employed. Capitalizing on the facile reduction−oxidation cycle of the Cp* ruthenium β-diketiminato complexes, catalytic atom transfer radical addition (ATRA) and cyclization (ATRC) reactions were performed on relevant substrates. The turnover rates are strongly dependent on the type of β-diketiminate used, where ligands with electron-withdrawing substituents, i.e., trifluoromethyl groups, provided complexes that efficiently catalyze the addition of CCl 4 or toluenesulfonyl chloride to styrene. In contrast, complexes with electron-donating substituents on the β-diketiminate promoted efficient ATR cyclization of N-allyl-N-phenyltrichloroacetamide and 2,2,2-trichloroethyl ether. Thus, the overall product conversion and yield are dependent on matching the ligand substitution pattern of the catalyst to the type of substrate.

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Single‐Site Organochromium Catalysts for High Molecular Weight Polyolefins

Enders

2014

Molecular Catalysts

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Cr Complexes of Nitrogen Donor Ligands for Olefin Oligomerisation and Polymerisation

Cited by 3 publications

References 91 publications

Synthesis of (Adamantylimido)vanadium(V) Dimethyl Complex Containing (2-Anilidomethyl)pyridine Ligand and Selected Reactions: Exploring the Oxidation State of the Catalytically Active Species in Ethylene Dimerization

Synthesis of (Adamantylimido)vanadium(V) Dimethyl Complex Containing (2-Anilidomethyl)pyridine Ligand and Selected Reactions: Exploring the Oxidation State of the Catalytically Active Species in Ethylene Dimerization

Modulating the Steric, Electronic, and Catalytic Properties of Cp* Ruthenium Half-Sandwich Complexes with β-Diketiminato Ligands

Single‐Site Organochromium Catalysts for High Molecular Weight Polyolefins

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