Alkylation of Indenyllithium and Alkylindenyllithium Compounds.

Meurling, Lennart; Helboe, Per; Larsen, Peder Olesen; Lüning, Björn; Rosenblom, Jan; Mannervik, Bengt

doi:10.3891/acta.chem.scand.28b-0295

Cited by 24 publications

(10 citation statements)

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“…monoalkylsubstituierte Indenderivate [37,38] durch ''direkte Alkylierung'' [39] von Indenyllithium [40] synthetisiert werden. Wird die Umsetzung in THF durchgef€ uhrt, so erh€ alt man die disubstituierten 1,1-und 1,3-Indenderivate als Nebenprodukte.…”

Section: Synthese Der A-(1-indenyl)-x-bromalkanderivate 1-6unclassified

Alkylidenverbrückte dissymmetrische zweikernige Metallocenkomplexe als Katalysatoren für die Ethylenpolymerisation

Deppner

Burger

Alt

2004

Journal of Organometallic Chemistry

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The synthesis is described of dissymmetric alkylidene bridged dinuclear metallocene complexes of titanium, zirconium and hafnium and some of the corresponding mononuclear reference complexes. The influence of structural parameters on the polymerization behaviour of the MAO activated complexes is systematically investigated for homogeneous ethylene polymerization. The dinuclear catalysts show higher polymerization activities than a mixture consisting of analogous mononuclear reference catalysts. The polyethylenes obtained from dinuclear complexes have higher polydispersities than those that were produced with mononuclear complexes. ZusammenfassungDie Synthese von dissymmetrischen, alkylidenverbr€ uckten Metallocenzweikernkomplexen der Metalle Titan, Zirconium und Hafnium sowie von einkernigen Referenzkomplexen wird beschrieben. Der Einfluss von Strukturparametern auf das Polymerisationsverhalten der mit MAO aktivierten Komplexe in der homogenen Ethylenpolymerisation wird systematisch untersucht. Die dinuklearen Katalysatoren zeigen h€ ohere Ethylenpolymerisationsaktivit€ aten als eine Mischung der entsprechenden einkernigen Referenzkatalysatoren. Die von den Zweikernkomplexen erhaltenen Polymere weisen h€ ohere Polydispersit€ aten auf als die der Einkernkomplexe.

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Section: Synthese Der A-(1-indenyl)-x-bromalkanderivate 1-6unclassified

Alkylidenverbrückte dissymmetrische zweikernige Metallocenkomplexe als Katalysatoren für die Ethylenpolymerisation

Deppner

Burger

Alt

2004

Journal of Organometallic Chemistry

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“…These observations indicate that 2a functions as a rare example of anionic boron nucleophile [39][40][41][42][43] in its reactions with alkyl halides, despite the more pronounced localization of negative charge on the C-2 carbon of the 1-bora-7aazaindenide anion. Given that the indenide anion itself alkylates exclusively at the C-1/C-3 positions, 44 it is notable that no evidence for alkylation of the C-3 position in anions 2 was observed. Density functional theory investigation of the reaction of 2a with CH2Cl2 shows that the lowest energy reaction path involves direct SN2 type attack of the boron on the alkyl halide ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Divergent reactivity of nucleophilic 1-bora-7a-azaindenide anions

et al. 2018

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The reactions of 1-bora-7a-azaindenide anions, prepared in moderate to excellent yields by reduction of the appropriate 1-bora-7a-azaindenyl chlorides with KC in THF, with alkyl halides and carbon dioxide were studied. With alkyl halides (CHCl, CHI and BrCH(D)CH(D)Bu), the anions behave as boron anions, alkylating the boron centre via a classic S2 mechanism. This was established with DFT methods and via experiments utilizing the neo-hexyl stereoprobe BrCH(D)CH(D)Bu. These reactions were in part driven by a re-aromatization of the six membered pyridyl ring upon formation of the product. Conversely, in the reaction of the 1-bora-7a-azaindenide anions with CO, a novel carboxylation of the C-2 carbon alpha to boron was observed. Computations indicated that while carboxylation of the boron centre was kinetically feasible, the products of B-carboxylation were not thermodynamically favored relative to the observed C-2 carboxylated species, which were formed preferably due to the generation of both C-C and B-O bonds. In these products, the pyridyl ring remains non-aromatic, in part accounting for the observed reversibility of carboxylation.

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“…The concentrations of the HBF 4 in Et 2 O (Aldrich) and n ‐BuLi in hexanes (Aldrich) solutions were determined by addition of a known excess of NaOH aqueous solution to a known volume of the corresponding target solution and back‐titration with aqueous solutions of HCl using an ethanol solution of phenolphthalein (0.1 %) as the indicator. 1‐methylindene, 1‐trimethylsilylindene, 1,3‐dimethylindene, Mg(Ind) 2 and NiBr 2 Py 4 (py = pyridine) were prepared according to literature procedures.…”

Section: Methodsmentioning

confidence: 99%

Cationic R‐Substituted‐Indenyl Nickel(II) Complexes of Arsine and Stibine Ligands: Synthesis, Characterization, and Catalytic Behavior in the Oligomerization of Styrene

et al. 2018

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A series of new cationic Rn‐substituted‐indenyl nickel(II) complexes containing arsine or stibine ligands were synthesized in moderate to very high yields by the protonation of the corresponding bis(indenyl) nickel derivatives [Ni(η‐Rn‐Ind)2] with HBF4, in the presence of 2 equiv. of AsPh3 or SbPh3 donor ligands. These complexes, with the general formula [Ni(η‐Rn‐Ind)(EPh3)2]BF4 (E = As, Sb), were structurally characterized by NMR spectroscopy and X‐ray diffraction, and subsequently tested as single‐component catalysts for the oligomerization of styrene, leading to the formation of very low molecular weight head‐to‐tail oligomers (typically consisting of dimers, trimers and tetramers). The new 1‐ or 2‐monosubstituted‐indenyl NiII catalyst precursors exhibit extremely high catalytic activities, considerably higher than those observed for the symmetrical unsubstituted‐ and the 1,3‐disubstituted‐indenyl nickel analogues (i.e. monosubstituted >> non‐substituted > 1,3‐disubstituted), their reactivity pattern showing similarities with that of the corresponding allyl derivatives. A simpler and more straightforward experimental procedure for the high yield preparation of [NiBr2(DME)], an important nickel starting material, which was used in the preparation of the bis(indenyl) nickel precursors of this work, is also described.

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Alkylation of Indenyllithium and Alkylindenyllithium Compounds.

Cited by 24 publications

References 0 publications

Alkylidenverbrückte dissymmetrische zweikernige Metallocenkomplexe als Katalysatoren für die Ethylenpolymerisation

Alkylidenverbrückte dissymmetrische zweikernige Metallocenkomplexe als Katalysatoren für die Ethylenpolymerisation

Divergent reactivity of nucleophilic 1-bora-7a-azaindenide anions

Cationic R‐Substituted‐Indenyl Nickel(II) Complexes of Arsine and Stibine Ligands: Synthesis, Characterization, and Catalytic Behavior in the Oligomerization of Styrene

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