Towards Selective Ethylene Tetramerization

Licciulli, Sebastiano; Thapa, Indira; Albahily, Khalid; Korobkov, Ilia; Gambarotta, Sandro; Duchateau, Robbert; Chevalier, Reynald; Schuhen, Katrin

doi:10.1002/anie.201003465

Cited by 75 publications

(53 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar correlation between temperature and selectivity has also been reported for the Cr-NNN tetramerization system, in which 1-octene is only produced when the reactor temperature is uncontrolled and allowed to raise above 100°C. 33 Upon activation with MAO in toluene, 3a also afforded C 6 and C 8 with good overall selectivity ( Table 2, entries 5 and 6). Using methylcyclohexane as solvent led to a drop of activity and switched the selectivity slightly from C 6 to C 8 .…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…17 Albeit in the absence of a P donor, chromium complexes bearing aminodipyridine ligands (Cr-NNN) afford pure 1-octene or 1-hexene, depending on the steric bulk of the ancillary ligand, alongside significant amounts of PE wax. 33 Similarly, removing the ortho-methoxy substituents from the phenyl group of Cr-PNP complexes shifted the catalytic selectivity from ethylene trimerization (ca. 90% 1-hexene) into tetramerization (up to 70% 1-octene).…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Selective Ethylene Oligomerization with Chromium Complexes Bearing Pyridine–Phosphine Ligands: Influence of Ligand Structure on Catalytic Behavior

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Selective Ethylene Oligomerization with Chromium Complexes Bearing Pyridine–Phosphine Ligands: Influence of Ligand Structure on Catalytic Behavior

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…Duchateau, Gambarotta, et al have structurally characterized a Cr(III) monomethyl complex with a N-alkylated 2,2,'-dipyridylamine ligand that, in the presence of MAO, produces 1-octene as the only α-olefin (along with low molecular weight polyethylene wax; Scheme 8). 60 In an attempt to study the catalytic activity of related Cr(II)-monoalkyls with diimine ligands in olefin polymerization, Theopold and coworkers have prepared a series of mono-and bimetallic methylchromium complexes and studied the redox non-innocent behaviour of the diimine ligand. 61 Further examples include dimethyl-molybdenum and dimethyl-tungsten imido complexes as catalysts for olefin dimerization.…”

Section: General Methods For the Generation Of Tm-ch3 Bonds In Transimentioning

confidence: 99%

Methyl Complexes of the Transition Metals

Campos

López‐Serrano

Peloso

et al. 2016

Chemistry A European J

View full text Add to dashboard Cite

Organometallic chemistry can be considered as a wide area of knowledge that combines concepts of classic organic chemistry, i.e. based essentially on carbon, with molecular inorganic chemistry, especially with coordination compounds. Transition metal methyl complexes probably represent the simplest and most fundamental way to view how these two major areas of chemistry combine and merge into novel species with intriguing features in terms of reactivity, structure, and bonding. Citing more than 500 bibliographic references, this review aims to offer a concise view of recent advances in the field of transition metal complexes containing M-CH3 fragments. Taking into account the impressive amount of data that are continuously provided by organometallic chemists in this area, this review is mainly focused on results of the last 5 years. After a panoramic overview on M-CH3 compounds of groups 3 to 11 which includes the most recent landmark findings in this area, two further sections are dedicated to methyl-bridged complexes and reactivity.

show abstract

“…We have previously established a double insertion route as the main mechanism in ethylene tetramerisation with Cr-PNP catalysts. Structural studies (vide infra) have shown that BIMA ligands can coordinate in a tridentate fac or mer fashion (see Figure 4) [49][50][51] Very low activities were observed for both catalysts (see Table 6). Similar reduction in catalytic activity was observed by…”

mentioning

confidence: 99%

Alternating α-Olefin Distributions via Single and Double Insertions in Chromium-Catalyzed Ethylene Oligomerization

et al. 2016

View full text Add to dashboard Cite

The catalytic oligomerization of ethylene with chromium-based complexes containing bis(benzimidazolemethyl)amine (BIMA) ligands results in alternating distributions of linear α-olefins (LAOs). Extremely high activities are obtained (>100 000 g mmol–1 h–1 bar–1) with N-alkyl-substituted BIMA ligands, whereas bulky groups on the central nitrogen or alternative central donors result in much lower activities. Variations in the ligand backbone, as well as methylation of the benzimidazole units, lead to reduction in activity. The alternating LAO distributions have been mathematically analyzed using second-order recurrence relations. The shape of the distributions is affected by ethylene pressure (1–4 bar) and by the cocatalyst to some degree. On the basis of the results and analysis presented herein, we propose that the alternating behavior originates from the ability of these chromium BIMA catalysts to undergo single as well as double ethylene insertion reactions. A minor second distribution (<5 wt %) of 2-ethyl-1-alkenes is obtained under certain conditions, resulting from incorporation of 1-butene. DFT studies (M06L) and experimental observations regarding the reaction between AlMe3 and the N-methyl BIMA ligand 2 have shown that deprotonation of the benzimidazole N–H units can occur, which suggests a change in coordination of the BIMA ligand under oligomerization conditions.

show abstract

Towards Selective Ethylene Tetramerization

Cited by 75 publications

References 42 publications

Selective Ethylene Oligomerization with Chromium Complexes Bearing Pyridine–Phosphine Ligands: Influence of Ligand Structure on Catalytic Behavior

Selective Ethylene Oligomerization with Chromium Complexes Bearing Pyridine–Phosphine Ligands: Influence of Ligand Structure on Catalytic Behavior

Methyl Complexes of the Transition Metals

Alternating α-Olefin Distributions via Single and Double Insertions in Chromium-Catalyzed Ethylene Oligomerization

Contact Info

Product

Resources

About