Ethylene oligomerization promoted by nickel-based catalysts with silicon-bridged diphosphine amine ligands

Wei, Wei; Yu, Bin; Alam, Fakhre; Huang, Yongwang; Cheng, Si‐Xue; Jiang, Tao

doi:10.1007/s11243-018-0276-7

Cited by 13 publications

(21 citation statements)

References 22 publications

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“…However, this mechanism much worse describes the distribution of products formed during the oligomerization of 1-hexene, because it requires the preferable β-C 2 H 5 elimination. The possible formation of odd carbon number olefins, as a result of side-reactions in the presence of the EtAlCl 2 , is not supported neither by literature [57,[66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82] nor by experimental data (SI, Figure S51).…”

Section: Formation Of Odd Carbon Number Olefinsmentioning

confidence: 89%

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NNNO‐Heteroscorpionate nickel (II) and cobalt (II) complexes for ethylene oligomerization: the unprecedented formation of odd carbon number olefins

Zubkevich

Тuskaev

Гагиева

et al. 2020

Applied Organom Chemis

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The unprecedented observation of odd carbon number olefins is reported during nickel‐ catalyzed ethylene oligomerization. Two complexes based on Co (II) and Ni (II) with novel tetradentate heteroscorpionate ligand have been synthesized and fully characterized. These complexes showed the ability to oligomerize ethylene upon activation with various organoaluminum compounds (Et2AlCl, Et3Al2Cl3, EtAlCl2, MMAO). Ni (II) based catalytic systems were sufficiently more active (up to 1900 kg·mol (Ni)−1·h−1·atm−1) than Co (II) analogs and have been found to be strongly dependent on the activator composition. The use of PPh3 as an additive to catalytic systems resulted in the increase of activity up to 4,150 kg·mol (Ni)−1·h−1·atm−1 and in the alteration of selectivity. All Ni (II) based systems activated with EtAlCl2 produce up to 5 mol. % of odd carbon number olefins; two probable mechanisms for their formation are suggested – metathesis and β‐alkyl elimination.

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Section: Formation Of Odd Carbon Number Olefinsmentioning

confidence: 89%

“…Such effect of the activator composition on activity was previously observed in. [17,51,[57][58][59][60] The use of 1 mol. Equiv.…”

Section: Oligomerization Of Ethylene In Chlorobenzenementioning

confidence: 99%

NNNO‐Heteroscorpionate nickel (II) and cobalt (II) complexes for ethylene oligomerization: the unprecedented formation of odd carbon number olefins

Zubkevich

Тuskaev

Гагиева

et al. 2020

Applied Organom Chemis

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“…[32] Highest temperature screening provides the lowest C 4 selectivity, it enhances the formation of C 6 products at the expense of the C 4 fraction (Table 4, Changing the cocatalyst molar ratio in the oligomerization reaction can tune the catalytic environment and therefore influence the catalytic performance. [20,22] Probing the role of DEAC by changing its molar ratio suggested that the concentration of cocatalyst significantly influences the catalytic activity and C 4 selectivity ( Table 5). The precatalysts 1, 2, and 4 offer high catalytic activity at 500 equiv DEAC (Table 5, entries 2, 6, 14), while precatalyst 3 exhibited the highest activity at 700 equiv DEAC ( Table 5, entry 11).…”

Section: S C H E M E 4 Proposed Ni(ii)-based Dinuclear Complex Lmentioning

confidence: 99%

“…[ 19 ] Our group recently established that the Ni(II) complexes of silicon‐bridged ligands can offer excellent catalytic performance for selective ethylene dimerization (Scheme 1). The Ni(II) complexes based on PCSiP ( A ), [ 20 ] silicon‐bridged PNP ( B ), [ 21 ] and silylated‐PNP ( C ) [ 22 ] ligands have been shown to be efficient dimerization catalysts that can provide as much as 2.40 × 10 8 g (mol Ni ) ‐1 h ‐1 high catalytic activity (in the case of B ) and more than 97% C 4 selectivity (in the case of A ).…”

Section: Introductionmentioning

confidence: 99%

Catalytic behavior tuning via structural modifications of silylated‐diphosphine Ni(II) complexes for ethylene selective dimerization

Wang

Alam

Chang

et al. 2020

Applied Organom Chemis

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The methylene spacers and an uncoordinated diphenylphosphine moiety in the scaffold of the CH 3 Si(CH 2) n (PPh 2) 3 and Si(CH 2 PPh 2) 4-type silylated diphosphine Ni(II) complex systems have a marked impact on their catalytic performance in selective ethylene dimerization. Ni(II)-based precatalyst 1, bearing two methylene spacers in its framework, exhibited the highest catalytic activity of 1.29 × 10 8 g (mol Ni)-1 h-1 , while precatalyst 3, with three methylene spacers, affords the highest product selectivity (88%) toward the C 4 fraction. Crystallographic investigations revealed that the precatalyst 3 adopts the mononuclear bidentate binding mode and the steric constraints of its uncoordinated diphenylphosphine moiety may successfully tailor the catalytic environment of the catalyst. The precatalyst 4 may form a dinuclear complex and exhibits high catalytic activity by changing the ligand/Ni molar ratio. The high C 4 selectivity of precatalyst 3 has been rationalized by density functional theory (DFT) calculations and found to be consistent with the experimental results. The study also revealed that designing new systems of Ni(II)-based complexes and their systematic modifications may further provide potential and industrially viable catalyst systems for selective ethylene oligomerization.

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“…Nickel complexes are being widely employed for processes of chain-walking ethylene polymerization [4,5,[14][15][16][17][18][19][20][21][22][23]6,[24][25][26][27][7][8][9][10][11][12][13] and copolymerization of ethylene with polar monomers [22,24,[35][36][37][38][39][40][41][42][43][44][27][28][29][30][31][32][33][34]. However, the interest in the development of new nickel-based catalytic systems for ethylene oligomerization is still high [4,6,[53][54][55]…”

Section: Introductionmentioning

confidence: 99%

Trapping the Short-Chain Odd Carbon Number Olefins Using Nickel(II)-catalyzed Tandem Ethylene Oligomerization and Friedel-Crafts Alkylation of Toluene

Zubkevich¹,

Тuskaev²,

Гагиева³

et al. 2020

Preprint

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<div>Nickel(II) complexes with pyrazole-based ligands are widely employed in catalysis of ethylene</div><div>oligomerization and subsequent Friedel-Crafts alkylation of toluene. We have prepared ten new</div><div>nickel(II) dibromide complexes with various substituted bis(azolyl)methanes. They have been</div><div>characterized using <sup>1</sup>H NMR, IR, MALDI-TOF and elemental analysis. The structures of three</div><div>complexes have been unambiguously established using X-ray diffraction. It was found that these</div><div>complexes in the presence of Et<sub>2</sub>AlCl or Et<sub>3</sub>Al<sub>2</sub>Cl<sub>3</sub> are active both in ethylene oligomerization and</div><div>Friedel-Crafts alkylation processes (activity up to 3720 kgoligomer·mol[Ni]<sup>−1</sup>·h<sup>−1</sup>). The use of Et<sub>3</sub>Al<sub>2</sub>Cl<sub>3</sub></div><div>results in the higher share of alkylated products (up to 60%). Moreover, catalytic systems activated with</div><div>Et<sub>3</sub>Al<sub>2</sub>Cl<sub>3</sub> produced small amounts of odd carbon number olefins (up to 0.8%). The Friedel-Crafts</div><div>alkylation was used as a trap for previously undetected short-chain odd carbon number olefins (C<sub>3</sub> and</div><div>C<sub>5</sub>).</div>

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Ethylene oligomerization promoted by nickel-based catalysts with silicon-bridged diphosphine amine ligands

Cited by 13 publications

References 22 publications

NNNO‐Heteroscorpionate nickel (II) and cobalt (II) complexes for ethylene oligomerization: the unprecedented formation of odd carbon number olefins

NNNO‐Heteroscorpionate nickel (II) and cobalt (II) complexes for ethylene oligomerization: the unprecedented formation of odd carbon number olefins

Catalytic behavior tuning via structural modifications of silylated‐diphosphine Ni(II) complexes for ethylene selective dimerization

Trapping the Short-Chain Odd Carbon Number Olefins Using Nickel(II)-catalyzed Tandem Ethylene Oligomerization and Friedel-Crafts Alkylation of Toluene

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