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  • 1
    Electronic Resource
    Electronic Resource
    Turning the key on p53 (2004)
    [s.l.] : Nature Publishing Group
    Nature 427 (2004), S. 789-790 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Almost exactly 25 years ago, a report appeared describing the interaction between a cancer-causing virus and a host protein dubbed 53K. That entity, since called p53 and recognized as a tumour-suppressor protein because of its ability to prevent undue cell proliferation, has attracted ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/427789a
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  • 2
    Electronic Resource
    Electronic Resource
    Immunization of hu-PBL–SCID mice and the rescue of human monoclonal Fab fragments through combinatorial libraries (1992)
    [s.l.] : Nature Publishing Group
    Nature 355 (1992), S. 258-262 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The degree of functionality of the human cell xenograft in SCID mice, notably the ability to produce a specific immune response, has been controversial and potentially limiting9'10'12'14. Using our refined peripheral blood lymphocyte (PEL) transfer protocol (M.A.D., S.A.E., ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/355258a0
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  • 3
    Electronic Resource
    Electronic Resource
    Three-dimensional helical supramolecules - elucidation of magnetic ordering for an antiferromagnetic phase (1996)
    Weinheim : Wiley-Blackwell
    Advanced Materials 8 (1996), S. 647-651 
    Details
    ISSN: 0935-9648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19960080809
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  • 4
    Electronic Resource
    Electronic Resource
    Enoläther, IX. Stereospezifische Cycloaddition von Sulfonylisocyanaten an Enoläther  -  Konfiguration, Isomerisierung und Umlagerung der Cycloaddukte (1971)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 1987-2001 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enol Ethers, IX. Stereospecific Cycloaddition of Sulfonylisocyanates to Enol Ethers  -  Configuration, Isomerization and Rearrangement of Cycloadducts Primarily FormedN-Tosylazetidin-2-ones 10a-13a and 10b-13b, resp. 2.2-diphenylcyclobutanones 22a-25a and 22b-25b are formed via stereospecific cis-addition upon reaction of enol ethers 6a-9a and 6b-9b with p-tosylisocyanate, resp. diphenylketene. Whereas the cyclobutanones are stable, the sterically pure azetidinones undergo isomerization, slow in the solid state, faster in solution, the trans-compound predominating in the equilibrium mixture. Much slower, by irreversible rearrangement of the azetidin-2-ones, β-alkoxyacrylamides 14-17 are formed. Structure and conformation of the enol ethers, azetidinones and cyclobutanones are discussed, the arguments being based on 1H n.m.r. spectra. In the cyclic compounds, conformational effects seem to have the main influence upon the position of the n.m.r. signals.
    Notes: N-Tosyl-azetidinone-(2) 10a-13a und 10b-13b bzw. 2.2-Diphenyl-cyclobutanone 22a-25a und 22b-25b entstehen unter stereospezifischer cis-Addition bei der Umsetzung von p-Tosylisocyanat bzw. Diphenylketen mit den Enoläthern 6a-9a und 6b-9b. Während die Cyclobutanone beständig sind, isomerisieren die sterisch einheitlichen Azetidione in Substanz langsam, rascher in Lösung zu einem an trans-Verbindung reicheren Gleichgewichtsgemisch. Sehr viel langsamer verläuft die irreversible Umlagerung der Azetidinone zu den β-Alkoxy-acrylamiden 14-17. Anhand der 1H-NMR-Spektren werden Struktur und Konformation der Enoläther, der Azetidinone und der Cyclobutanone diskutiert; bei den cyclischen Verbindungen scheinen primär konformative Effekte die Lage der NMR-Signale zu beeinflussen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19711040640
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  • 5
    Electronic Resource
    Electronic Resource
    Aminobenzole, X. Der Einfluß von Donorsubstituenten auf Nitrosoaromaten  -  Elektronen- und 1H-NMR-Spektren von Aminonitrosobenzolen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1305-1317 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aminobenzenes, X. The Effect of Donor Substituents upon Nitrosoarenes  -  Electron and 1H.-N.M.R. Spectra of AminonitrosobenzenesThe donor influence of the aromatic π-system increases from mono to tris(dialkylamino)-nitrosobenzenes  -  1to 3  -  as reflected by the increasing hypsochromic shift of the n-π* absorption. Within each of the three classes of compounds, the position of this band corresponds to the gradation of the electron-releasing power for the various NR2 groups: pyrrolidino 〉 dimethylamino 〉 piperidino 〉 morpholino. For the triaminonitrosobenzenes 3, this sequence also follows from the barriers of rotation around the C(aryl)-NO bond. Furthermore, there is good correlation between the energy of activation for the rotational process, determined n.m.r. spectroscopically, and the energy of the n-π* absorption.
    Notes: Die von dem Mono-über die Bis- zu den Tris(dialkylamino)nitrosobenzolen - 1.2bzw. 3 - ansteigende Donor-Wirkung des aromatischen π-Systems spiegelt sich in der zunehmend hypsochromen Verschiebung der n-π *-Absorption. Innerhalb der drei Verbindungsklassen entspricht die Lage dieser Bande der Abstufung in der elektronenabgebenden Kraft der einzelnen NR2- Gruppen: Pyrrolidino 〉 Dimethylamino 〉 Piperidino 〉 Morpholino. Für die Triaminonitrosobenzole 3errechnet sich diese Reihenfolge gleichfalls aus der Rotationsbarriere um die C(Aryl)-NO-Bindung. Zwischen der NMR-spektroskopisch bestimmten Aktivierungsenergie für diese Rotation und der n-π2-Energie wird gute Korrelation gefunden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070427
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  • 6
    Electronic Resource
    Electronic Resource
    Aminobenzole, XII. Kinetik und Mechanismus der Alkylierung von 1,3,5-Tripyrrolidinobenzol (1977)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 181-198 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aminobenzenes, XII. Alkylation of 1,3,5-Tripyrrolidinobenzene - Kinetics and MechanismUpon reaction of 1,3,5-tripyrrolidinobenzene (1) with alkyl iodides, stable σ complexes 2a-c are formed besides quaternary N-alkylammonium salts 3a-c. Both by the formal kinetics of the reaction and reactivity gradation CH3 ≥ C2H5 ≥ CH(CH3)2 (28.5:1.0:0.12), an SN2 mechanism is established for this first (rate limiting) step of electrophilic aromatic substitution. Likewise, activation parameters characteristic of a typical SN2 reaction are found for the methyl σ complex formation (2a). In the case of isopropyliodide, an SN1 process competes with bimolecular substitution. Benzyl halides, on the other hand, yield exclusively σ complexes (2e-k); the C-reaction proceeds solely by an SN2 mechanism independent of the p-substituent (OCH3 → NO2). The correlation of 1g k with Hammett's σ constants shows a non-linear relationship, with an alltogether small substituent dependency.
    Notes: Bei der Umsetzung von 1,3,5-Tripyrrolidinobenzol (1) mit Alkyliodiden werden neben N-Alkyl-ammoniumsalzen 3a-c isolierbare σ-Komplexe 2a-c gebildet. Für diesen ersten (geschwindigkeitsbestimmenden) Schritt der elektrophilen aromatischen Substitution ist sowohl durch die Formalkinetik wie durch die Reaktivitätsabstufung CH3 ≥ C2H5 ≥ CH(CH3)2 (28.5:1.0:0.12) ein SN2-Mechanismus gesichert. Die Aktivierungsparameter für die Bildung des Methyl-σ-Komplexes 2a sind ebenfalls charakteristisch für eine klassische SN2-Reaktion. Bei der Isopropylierung konkurriert ein SN1-Prozeß mit der bimolekularen Substitution. Benzylhalogenide dagegen geben ausschließlich C-Reaktion zu den σ-Komplexen 2e-k; dabei wird unabhängig vom p-Substituenten (OCH3 → NO2) nur SN2-Reaktion gefunden. Die Korrelation von 1g k mit Hammettschen σ-Konstanten zeigt einen nicht-linearen Verlauf (bei insgesamt nur geringer Substituentenabhängigkeit).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19771100118
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  • 7
    Electronic Resource
    Electronic Resource
    Enoläther, X. Kinetik und Mechanismus der Cycloaddition von p-Toluolsulfonylisocyanat an Enoläther; Kinetik der Epimerisierung und Umlagerung der gebildeten 4-Alkoxy-1-tosyl-3-alkyl-azetidinone-(2) (1971)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 2002-2012 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enol Ethers, X. Kinetics and Mechanism of the Cycloaddition of p-Toluenesulfonyl Isocyanate to Enol Ethers; Kinetics of the Epimerization and Rearrangement of the Resulting 4-Alkoxy-1-tosyl-3-alkyl-azetidin-2-onesFor cycloadditions of tosyl isocyanate 1 to enol ethers 2-9, for the epimerization of the azetidinones 13-20 formed thereby, and for their subsequent rearrangement to β-alkoxy-acrylamides, rate constants are determined n.m.r. spectroscopically both in CCl4 and CD3CN. Stereochemical results, activation parameters as well as the differing influence of substituents and solvent polarity on the rate of cycloaddition and isomerization indicate the cycloaddition to proceed in a concerted way via a transition state with partial charges.
    Notes: Die Reaktionsgeschwindigkeiten der Cycloaddition von Tosylisocyanat 1 an die Enoläther 2-9, die Epimerisierung der hierbei gebildeten Azetidinone 13-20 und deren nachfolgende Umlagerung zu β-Alkoxy-acrylamiden jeweils in CCl4 und CD3CN werden NMR-spektroskopisch bestimmt. Stereochemische Befunde, Aktivierungsparameter sowie die unterschiedliche Beeinflussung von Cycloadditions- und Isomerisierungsgeschwindigkeit durch Substituenten und Solvenspolarität machen für die Cycloaddition einen Synchronmechanismus mit Partialladungen im Übergangszustand wahrscheinlich.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19711040641
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  • 8
    Electronic Resource
    Electronic Resource
    Aminobenzole, VI. Darstellung N-persubstituierter 1.3.5-Triamino-benzole über Dehydrobenzol-Zwischenstufen (1970)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1440-1455 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Amino Benzenes, VI. Preparation of N-persubstituted 1,3,5-Triaminobenzenes via Dehydrobenzene IntermediatesTris(dialkylamino)benzenes 1a-j and 4, halo-m phenylene diamines 2a-g and 9a, b, and halo-tris(dialkylamino)benzenes 10a-i are synthesized by the reaction of halobenzenes with sec. amines and phenyl lithium. Conclusions are drawn about the reaction steps, i.e., metalation, elimination, and addition to the benzyne, from the structure and isomer distribution of the products.
    Notes: Über die Reaktion von Halogenbenzolen mit sek. Aminen und Phenyllithium sind die Tris - dialkylamino-benzole 1a-j und 4, die halogenierten m-Phenylendiamine 2a-g und 9a, b sowie die Halogen-tris-dialkylamino-benzole 10 a-i zugänglich.  -  Aus der Struktur und der Isomerenverteilung der erhaltenen Produkte werden Schlüsse auf die einzelnen Reaktionsschritte (Metallierung, Eliminierung und Addition) gezogen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19701030516
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  • 9
    Electronic Resource
    Electronic Resource
    Aminobenzole, VII. N-Persubstituierte 3-Amino-phenole und 1.3-Diamino-benzole (1970)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1456-1462 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Amino Benzenes, VII. N-Persubstituted 3-Aminophenols and 1,3-DiaminobenzenesThe reaction of resorcinol with sec. amines yields 3-dialkylaminophenols 1a-e and 1,3-bis-(dialkylamino)benzenes 2a, b. 2a, b may be synthesized in better yields by the latter reaction of o-dichlorobenzene with lithium dialkylamides; 2f can be obtained only by the reaction. Lithium morpholide does not afford amino benzenes under the conditions of the benzyne reaction.
    Notes: Durch Umsetzung von Resorcin mit sek. Aminen werden die 3-Dialkylamino-phenole 1a-e und die 1.3-Bis-dialkylamino-benzole 2a, b erhalten. 2a, b sind besser, 2f ist nur durch Reaktion von o-Dichlorbenzol mit Lithium-dialkylamiden zugänglich. Lithium-morpholid setzt sich unter den Bedingungen der Arin-Reaktion nicht zum Aminoaromaten um.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19701030517
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  • 10
    Electronic Resource
    Electronic Resource
    Aminobenzole, IX. Darstellung und Reaktionen von 1,3,5- Tris(dialkylamino)-2-nitrosobenzolen (1974)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1285-1304 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aminobenzenes, IX. Formation and Reactions of 1,3,5-Tris(dialkylamino)-2-nitrosobenzenesThe triaminobenzenes 2 react with dinitrogen tetroxide (N2O4) to yield the nitroso compounds 4 while even arenes as reactive as N, N- dimethylaniline are nitrated by N2H4. This discrepancy in the product formation can be rationalized in terms of increasing nucleophilic potential of the aromatic substrates and in terms of different dissociation pathways of the N2O4. This discrepancy in the product formation can be rationalized in terms of increasing nucleophilic potential of the aromatic substrates and in terms of different dissociation pathyways of the N2O4 moiety. Alkylation and protonation of compounds 4and 7 takes place exclusively at the nitroso oxygen; the u. v. and 1H n. m. r. spectra of the quinone imonium salts 9, 10thus formed are analyzed and discussed. Reduction of the nitrosobenzenes 4with a Pd/C catalyst affords the anilines 14. Diazotation of these amines was not successful on a preparative scale whereas the 4-nitroso-N,N-dialkylanilines 15 react with NO to form the remarkably stable diazonium salts 16in good yield.
    Notes: Die Triaminobenzole 2reagieren mit Distickstofftetroxid (N2O4) zu den Nitrosoverbindungen 4, während selbst so reaktive Aromaten wie N,N-Dimethylanilin mit N2O4 nitriert werden. Diese Divergenz in der Produktbildung läßt sich über die unterschiedlichen Nucleophilie der Aromaten und die verschiedenen Dissoziationsmöglichkeiten des N2O4 deuten. Die Verbindungen 4 und 7 werden ausschließlich am Nitrososauerstoff alkyliert und protoniert; die UV-und 1H-NMR-Spektren der dabei gebildeten Chinoniumsätze 9, 10 werden diskutiert und gedeutet. Über Pd/Aktivkohle lassen sich die Nitrosobenzole 4 zu den entsprechenden Anilinen 14 hydrieren. Eine präparative brauchbare Diazotierung dieser Amine gelingt nicht, dagegen reagieren die 4-Nitroso-N,N-dialkylaniline 15 mit NO in guten Ausbeuten zu den bemerkenswert stabilen Diazonium-nitraten 16.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19741070426
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