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  • 1
    Electronic Resource
    Electronic Resource
    Use of Magnesium Anthracene·3THF in Synthesis: Generation of Grignard Compounds and Other Reactions with Organic Halides (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1507-1516 
    Details
    ISSN: 0009-2940
    Keywords: Magnesium anthracene ; Grignard compounds ; Magnesium, active ; Radical transfer reaction ; Allenylmagnesium chloride ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The course (a), (b), (c) (Scheme 1) of the reaction of magnesium anthracene·3THF (1) with organic halides (RX) is dependent on the nature of RX. With alkyl halides in THF 1 reacts as a nucleophile, whereby primary as well as secondary alkyl halides produce dialkyldihydroanthracenes (4-4′′) and tertiary alkyl halides yield primarily monoalkyl-substituted dihydroanthracenes (2, 2′). With bromo- and iodobenzene in THF 1 reacts predominantly as a radical with H atom abstraction from the solvent affording benzene and 9. The formation of Grignard compounds (5) and anthracene (6), originating from primary and secondary alkyl and aryl halides and 1 in toluene or ether at elevated temperatures, is not caused by the reaction of 1 but by the “active magnesium” (Mg*) formed by decomposition of 1 in these solvents. In contrast, allyl, propargyl, and benzyl halides react with 1 independently of the solvent under mild conditions to produce 5 and 6. Allyl- and the difficultly accessible allenylmagnesium chloride can be prepared in THF at -78 and 0°C, respectively, from the corresponding halides and ordinary Mg powder via catalytic amounts of 1.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230711
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  • 2
    Electronic Resource
    Electronic Resource
    Magnesium Adducts of Substituted Anthracenes - Preparation and Properties (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1529-1536 
    Details
    ISSN: 0009-2940
    Keywords: Magnesium anthracenes, substituted, reactions of, spectra of ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Methyl-, 1,4-dimethyl-, 9-methyl-, 9-ethyl-, 9,10-dimethyl-, and 9-phenylanthracene (1a-f) react with magnesium in THF at room temperature to afford the corresponding substituted magnesium anthracenes 2a-i. 9,10-Diphenylanthracene (1g), however, reacts with magnesium under the same conditions to produce the deep-blue magnesium bis(9,10-diphenylanthracenide) · 6 THF (4g). Upon heating to 60°C in THF, 4g reversibly dissociated to give magnesium 9,10-diphenylanthracene · 3 THF (2g) and 1g, while prolonged heating at 60°C causes decomposition of 2g to active magnesium (Mg*) and 1g. In THF 2a-c, e, and f exhibit temperature-dependent equilibria with 1a-c, e, and f and magnesium. Compared with magnesium anthracene · 3 THF (2), these equilibria are strongly shifted toward substituted anthracenes and magnesium, and only at 0°C high conversions are achieved. The magnesium exchange between 2 and the substituted anthracenes 1a,b, and f in THF has been experimentally verified. 2a,e, and f react with organic halides in the same way as 2, however, in the case of allyl, propargyl, and benzyl chloride the yields of Grignard compounds are lower than for 2; with bromobenzene, the tendency for the radical transfer reaction is stronger than for 2. Magnesium 9,10-dimethylanthracene (2e) reacts with ethyl acetate to give the bicyclic tertiary alcohol 9 by an intramolecular C-C coupling reaction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230713
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  • 3
    Electronic Resource
    Electronic Resource
    Active Magnesium from Catalytically Prepared Magnesium Hydride or from Magnesium Anthracene and its Uses in the Synthesis (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1517-1528 
    Details
    ISSN: 0009-2940
    Keywords: Magnesium anthracene ; Grignard componds ; Magnesium, active ; 1-Oxa-2-magnesiacyclohexane ; Magnesium hydride ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly reactive, pyrophoric forms of magnesium with specific surface areas of 20-109 m2/g (Mg*) can be generated by the dehydrogenation of catalytically prepared magnesium hydride (MgH2*) or by decomposition of magnesium anthracene · 3 THF (4). The decomposition of 4, with recovery of anthracene and THF, may be accomplished both thermally and by ultrasound in an organic solvent (toluene, n-heptane) or thermally in the solid state in vacuo. Mg* obtained by the latter method exhibits only weak reflections in the X-ray powder diagram and has, in comparison to other mentioned Mg* species, the highest reactivity toward hydrogen. Diverse Grignard compounds can be prepared under mild conditions (⋜25°C) in THF or ether as well as in hydrocarbons by using Mg* from MgH2* from MgH2* or 4. The cleavage of THF with formation of 1-oxa-2-magnesiacyclohexane (2) is possible by employing Mg* from MgH2* or 4.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230712
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  • 4
    Electronic Resource
    Electronic Resource
    Neue Magnesiumanthracen-Komplexe durch Ligandenaustausch (1988)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 33-37 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Magnesium Anthracene Complexes by Ligand ExchangeComplexed tetrahydrofuran in magnesium anthracene · 3 THF (1) is displaced by mono-, bi-, and tridentate ligands L (L = dioxane, 1,2-dimethoxyethane, ethylbis(2-methoxyethyl)amine, pentamethyldiethylenetriamine, 1,4,7-trimethyl-1,4,7-triazacyclononane) affording the magnesium anthracene complexes C14H10Mg · n L (2a-e); upon reaction of 1 with tetramethylethylenediamine (TMEDA) magnesium anthrancene · THF · TMEDA is formed. The new magnesium complexes 2a-e are protolysed to Mg2+, 9,10-dihydroanthracene, and L. In solvents of low Lewis basicity (ether, hydrocarbons) 1 decomposes, probably via magnesium anthracene · 2 THF, to active magnesium, anthracene, and THF. A similar behaviour in toluene is displayed also by magnesium butadiene · 2 THF.
    Notes: Das in Magnesiumanthracen · 3 THF (1) komplexgebundene THF kann durch ein-, zwei- und dreizähnige Liganden L unter Bildung der Magnesiumanthracen-Komplexe C14H10Mg · n L (2a-e, L = Dioxan, 1,2-Dimethoxyethan, Ethylbis(2-methoxyethyl)amin, Pentamethyldiethylentriamin, 1,4,7-Trimethyl-1,4,7-triazacyclononan) verdrängt werden; bei der Reaktion von 1 mit Tetramethylethylendiamin (TMEDA) entsteht Magnesiumanthacen · THF · TMEDA. Die neuen Mg-Komplexe 2a-e ergeben bei der Protolyse Mg2-, 9,10-Dihydroanthracen und L. In Lösungsmitteln geringer Lewis-Basizität (Ether, Kohlenwasserstoffe) zersetzt sich 1, wahrscheinlich über die Zwischenstufe von Magnesiumanthracen · 2 THF, zu aktivem Magnesium, Anthracen und THF. ähnlich verhält sich auch Magnesiumbutadien · 2 THF in Toluol.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19881210107
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  • 5
    Electronic Resource
    Electronic Resource
    Synthese und Struktur von 1,4-Dimethylanthracenmagnesium·3 thf und μ-Trichloro-dimagnesium .6thf(+)-anthracenid (1985)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 97 (1985), S. 972-974 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19850971117
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  • 6
    Electronic Resource
    Electronic Resource
    9,10-(1′-Magnesiapropano)-9,10-dihydroanthracene, Synthese, Struktur und ReaktivitätMagnesium-Anthracen-Systeme, 3. Mitteilung.  -  2. Mitteilung: [2]. (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 99 (1987), S. 1046-1047 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19870991014
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis and Structure of 1,4-Dimethylanthracenemagnesium·3thf and μ-Trichlorodimagnesium·6thf(1+) Anthracenide (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 24 (1985), S. 960-961 
    Details
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.198509601
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