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Mezzetti, Antonio; Becker, Conny

doi:10.1002/1522-2675(200209)85:9<2686::aid-hlca2686>3.0.co;2-b

Cited by 62 publications

(46 citation statements)

References 25 publications

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“…The ethylene/VF copolymers produced by C in hexanes exhibit broad MWDs (Table 1, entries 3,4; Figure 2). Given the nearly ideal single-site behavior observed in ethylene homopolymerization tral cage, leading to the formation of new active Pd species [23,25,[48][49][50][51][52]. Consistent wit sal, -CH2CH2F and -CH2CHF2 end groups, which are formed by ethylene and VF inserti pecies in copolymerization by mononuclear catalysts A, are not observed in the copol ced by C (Figure 3) [23].…”

Section: Resultsmentioning

confidence: 95%

Copolymerization of Ethylene and Vinyl Fluoride by Self-Assembled Multinuclear Palladium Catalysts

Liu

Jordan

2020

Polymers

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The self-assembled multinuclear PdII complexes {(Li-OPOOMe2)PdMe(4-5-nonyl-pyridine)}4Li2Cl2 (C, Li-OPOOMe2 = PPh(2-SO3Li-4,5-(OMe)2-Ph)(2-SO3−-4,5-(OMe)2-Me-Ph)), {(Zn-OP-P-SO)PdMe(L)}4 (D, L = pyridine or 4-tBu-pyridine, [OP-P-SO]3− = P(4-tBu-Ph)(2-PO32−-5-Me-Ph)(2-SO3−-5-Me-Ph)), and {(Zn-OP-P-SO)PdMe(pyridine)}3 (E) copolymerize ethylene and vinyl fluoride (VF) to linear copolymers. VF is incorporated at levels of 0.1–2.5 mol% primarily as in-chain -CH2CHFCH2- units. The molecular weight distributions of the copolymers produced by D and E are generally narrower than for catalyst C, which suggests that the Zn-phosphonate cores of D and E are more stable than the Li-sulfonate-chloride core of C under copolymerization conditions. The ethylene/VF copolymerization activities of C–E are over 100 times lower and the copolymer molecular weights (MWs) are reduced compared to the results for ethylene homopolymerization by these catalysts.

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Section: Resultsmentioning

confidence: 95%

Copolymerization of Ethylene and Vinyl Fluoride by Self-Assembled Multinuclear Palladium Catalysts

Liu

Jordan

2020

Polymers

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“…Anstatt die natürliche Neigung des Fluors zu ladungsdominierten Wechselwirkungen durch Desolvatation zu verschlimmern, wären neue Reagentien nützlich, deren enthaltenes Fluor eine Tendenz zur C‐F‐Bildungbindung durch Orbitalkontrolle zeigt 6b. 14…”

Section: Methodsunclassified

Fluorierung in späten Synthesestadien: extravagante Neuheit oder nützliches Hilfsmittel?

Neumann

Ritter

2015

Angewandte Chemie

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Verzauberndes Fluor: Dieser Essay schildert die jüngsten Erfolge bei Fluorierungen im späten Synthesestadium und identifiziert die noch zu nehmenden Hürden zur Etablierung solcher Methoden in der Synthese komplexer Organofluoride. Ansätze werden beschrieben, wie ein vermehrtes Verständnis der Bindungswechselwirkungen des Fluors zu einer neuen Klasse milder und vielseitiger Fluorierungsreagentien führen könnte.

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“…Possibly occurring partially through a path involving coordinated alkyl halide [118,119], 28 and [Ru(diphos) 2 Cl]PF 6 catalyze exchange of fluoride from TlF with alkyl iodides and bromides, Scheme 22 [120][121][122]. Although modest asymmetric induction occurs in the reaction initially, the ee of the product deteriorates by the time the reaction is complete.…”

Section: Fluoride/halide Exchangementioning

confidence: 99%

Lewis Acid Catalysis by Ruthenium Complexes

Faller¹,

Parr²

2006

COC

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Recent progress in the Lewis acid catalysis of organic reactions by ruthenium complexes. The review focuses on reactions in which coordinatively unsaturated ruthenium species function as conventional Lewis acids, rather than those involving oxidation or reduction, such as in hydrogenations. Particular emphasis is placed on the development of asymmetric catalysts. INTRODUCTIONLewis acid catalysis continues to be of major utility in organic synthesis [1]. Recent interest in asymmetric catalysis [2,3], particularly for the formation of carbon-carbon bonds, has spurred continuing developments in chiral Lewis acid catalysts [4][5][6]. Classically, Lewis acid catalysts would have involved: main group elements, such as boron or aluminum; tin or zinc; early transition metals, such as titanium; or some lanthanides. Koga developed one of the earliest successful main group catalysts [7]. Yamamoto has been a major contributor to the development of chiral main group Lewis acid catalysts [1,8]. Organometallic Lewis acids of late transition metals have been extensively studied by Beck [9], but the potential for stoichiometric asymmetric reactions on coordinated ligands was largely developed by others, particularly with rhenium [10,11] and molybdenum reagents [12]. These studies of stoichiometric reactions provided valuable information regarding mechanistic aspects and control of nucleophilic attack on coordinated substrates. The lack of sensitivity to decomposition from moisture is a particular advantage of the late transition metal Lewis acids and the potential for straightforward elaboration of the chirality at the metal center via ligand variation has allowed the development of effective asymmetric catalysts based on these metals. Lewis-acid catalysts based on ruthenium have been particularly effective and recent developments on this area will be covered here. Since the mechanisms of a large number of reactions catalyzed by ruthenium complexes involve loss of a ligand to provide a site for coordination of a substrate, a large fraction of the reactions could be viewed as involving Lewis acids. Thus this overview could cover much of the material in a recent monograph [13] which included 383 pages dedicated to ruthenium in organic synthesis. Nevertheless, we will primarily focus on reactions that have been traditionally viewed as catalyzed by Lewis acids and only provide a brief discussion of reactions in which one would expect the oxidation state of the ruthenium to change during the catalytic cycle. Another specific review and more general reviews are also recommended [13][14][15][16].

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Untitled

Cited by 62 publications

References 25 publications

Copolymerization of Ethylene and Vinyl Fluoride by Self-Assembled Multinuclear Palladium Catalysts

Copolymerization of Ethylene and Vinyl Fluoride by Self-Assembled Multinuclear Palladium Catalysts

Fluorierung in späten Synthesestadien: extravagante Neuheit oder nützliches Hilfsmittel?

Lewis Acid Catalysis by Ruthenium Complexes

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