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  • 1
    Electronic Resource
    Electronic Resource
    Theory and application of photoelectron spectroscopy. 100. Variable-temperature photoelectron spectral study of 1,3-dithiol-2-one and 4,5-disubstituted 1,3-dithiol-2-ones. Thermal generation of 1,2-dithiete, 3,4-disubstituted 1,2-dithietes, and dialkyl tetrathiooxalates (1983)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 105 (1983), S. 4519-4528 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00352a004
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  • 2
    Electronic Resource
    Electronic Resource
    The Reaction of Malononitrile with Substituted Hydrazines: New Routes to 4-Aminopyrazolo[3,4-d]pyrimidines1,2 (1959)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 81 (1959), S. 2456-2464 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01519a045
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  • 3
    Electronic Resource
    Electronic Resource
    The Reaction of Malononitrile with Hydrazine1,2 (1959)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 81 (1959), S. 2452-2455 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01519a044
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  • 4
    Electronic Resource
    Electronic Resource
    Reactions of 3,5-Diaryl-1,2-dithiolium Salts and 3,5-Diaryl-1,2,4-dithiazolium Salts with Metal Cyclopentadienides (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 221-228 
    Details
    ISSN: 0947-3440
    Keywords: 3,5-Diaryl-1,2-dithiolium salts ; 3,5-Diaryl-1,2,4-dithiazolium salts ; Metal cyclopentadienides ; 3,7-Dithiatricyclo[4.4.0.02,8]deca-4,9-diene ; 3,5-Dithiatricyclo[4.2.2.02,6]deca-7,9-diene ; 3,7-Dithia-5-azatricyclo[4.4.0.02,8]deca-4,9-diene ; Diels-Alder reactions ; Nitrogen heterocycles ; Sulfur heterocycles ; Polycycles ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of the 3,5-diaryl-1,2-dithiolium salts 2 with the metal cyclopentadienides 4 and 9 leads to the formation of the tricyclic compounds 6 and 10 via a ring-opened intermediate, which undergoes an intramolecular Diels-Alder cyclization. Compounds 6 and 10 rearrange by treatment with boron trifluoride-diethyl ether to the isomeric compounds 7 and 11. The structures 6f and 7f were confirmed by X-ray analysis. Condensation of the 3,5-diaryl-1,2,4-dithiazolium salts 3 with the metal cyclopentadienides 4 affords the tricyclic compounds 12, which do not rearrange by Lewis acid catalysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970133
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  • 5
    Electronic Resource
    Electronic Resource
    Heterosubstituierte Fulvene, VII. Zur Isomerie und Tautomerie einiger heterosubstituierter Benzofulvene (1970)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 2687-2695 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterosubstituted Fulvenes, VII. Isomerism and Tautomerism of some Heterosubstituted Benzofulvenes2-Methoxy-3-acetylindene (2) condenses with aliphatic amines to give the N-substituted 2-amino-3-acetylindenes (3), which exist in solution as a mixture of tautomers and react with trialkyloxonium tetrafluoroborates to form the alkoxy(amino)benzofulvenes 5. Direct alkylation of 2 with oxonium salts yields the cis-trans isomerie bis(alkoxy)benzofulvenes 8. l-Acetylindan-2-one (9) condenses with aliphatic mercaptans to give the bis(alkylthio)-benzofulvenes 12, the E- and Z-isomers of which are in equilibrium with the indene tautomer 11. Acid hydrolysis of 12 leads to the formation of 2-alkylmercapto-3-acetylindenes 13 which react with oxonium salts to yield alkoxy(alkylmercapto)benzofulvenes 14. Questions of isomerie and tautomerie structures are discussed on the basis of i. r. and n. m. r. spectra.
    Notes: 2-Methoxy-3-acetyl-inden (2) kondensiert mit aliphatischen Aminen zu den N-substituierten 2-Amino-3-acetyl-indenen (3), die in Lösung als Tautomerengemische vorliegen und von Trialkyloxoniumtetrafluoroboraten in die Alkoxy-amino-benzofulvene 5 übergeführt werden. Durch Alkylierung von 2 mit Oxoniumsalzen erhält man die cis-trans-isomeren Bis-alkoxy-benzofulvene 8. l-Acetyl-indanon-(2) (9) bildet mit aliphatischen Mercaptanen die Bis-alkylmercapto-benzofulvene 12, deren E- und Z-Isomere mit dem Inden-Tautomeren 11 im Gleichgewicht stehen. Saure Hydrolyse von 12 liefert die 2-Alkylmercapto-3-acetyl-indene 13, die mit Oxoniumsalzen zu den Alkoxy-alkylmercapto-benzofulvenen 14 reagieren. Fragen der Isomerie und Tautomerie werden an Hand von IR- und NMR-Spektren diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19701030838
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  • 6
    Electronic Resource
    Electronic Resource
    Acylgruppenwanderung, IV. Hammett-Korrelation bei der Acylgruppenwanderung p-substituierter 3-Benzoyl-2-indenylacetate - Nachweis einer intramolekularen Wanderung der Estergruppe (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 138-145 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acyl Group Migration, IV. Hammett Correlation of Acyl Group Migration in 3-Benzoyl-2-indeny Acetates. - Evidence for an Intramolecular Mechanism2-Pyrrolidinoindene (1) has been acylated with acyl halides to form the 3-acyl-2-pyrrolidinoindenes (2) and hydrolysed with 25% formic acid to yield the 1-acyl-2-indanones (3), which have been esterified with acyl halides to give the 3-acyl-2-indenyl esters 4-11. The influence of p-substituents in the 3-aroyl-2-indenyl acetates 6-10 on the equilibrium position of the acetyl group migration between the isomers A and C follows a Hammett correlation. With the exception of 3-(p-nitrobenzoyl)-2-indenyl acetate (7A), which has been obtained cristalline in both isomeric forms A and C, all 3-acyl-2-indenyl esters exist only as isomer A in the solid state. A crossing experiment with the enolesters 6, 11, 12 and 13 demonstrates that the acyl group migration A ⇄ C in the enolesters of β-diketones follows exclusively an intramolecular pathway.
    Notes: 2-Pyrrolidinoinden (1) läßt sich mit Carbonsäurehalogeniden in die 3-Acyl-2-pyrrolidinoindene (2) überführen und mit 25 proz. Ameisensäure zu den 1-Acyl-2-indanonen (3) verseifen, die mit Carbonsäurehalogeniden in die 3-Acyl-2-indenylcarbonester 4-11 umwandelbar sind. Der p-Substituenteneinfluß der 3-Aroyl-2-indenylacetate 6-10 auf die Gleichgewichtslage der Acetylgruppenwanderung zwischen den Isomeren A und C gehorcht einer Hammett-Korrelation mit σp+-Werten. Mit Ausnahme des [3-(p-Nitrobenzoyl)-2-indenyl]acetats (7A), das in beiden isomeren Formen A und C kristallin erhalten wird, liegen alle übrigen 3-Acyl-2-indenylcarbonester kristallin nur in der Struktur A vor. Ein Kreuzungsexperiment der Enolester 6, 11, 12 und 13 beweist, daß die Acylgruppenwanderung A ⇄ C in β-Diketonenolestern ausschließlich intramolekular verläuft.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751080117
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  • 7
    Electronic Resource
    Electronic Resource
    Zur Reaktion von Biacetyl mit Malononitril unter Alkoholat-Katalyse (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 3256-3261 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Biacetyl with Malononitrile Catalysed by Sodium EthoxideReaction of biacetyl with malononitrile in the presence of sodium ethoxide leads to the formation of 1,5-dimethyl-3,7-dioxo-2,8-diaza-cis-bicyclo[3.3.0]octane-4,6-dicarbonitrile (6), which is also obtained by an alkali catalysed rearrangement of the isomeric 2,6-diaza compound 2. Hydrolysis of 6 by hydrochloric acid yields the corresponding dicarboxylic acid 9, decarboxylation 1,5-dimethyl-2,8-diaza-cis-bicyclo[3.3.0]octane-3,7-dione (10). Hydrolysis of 6 by hydrobromic acid leads to the formation of 1,5-dimethyl-2,8-dioxa-cis-bicyclo[3.3.0]octane-3,7-dione (8). The structure of 8 has been confirmed by some additional chemical transformations.
    Notes: Die Umsetzung von Biacetyl mit Malononitril unter Alkoholat-Katalyse führt zu 1,5-Dimethyl-3,7-dioxo-2,8-diaza-cis-bicyclo[3.3.0]octan-4,6-dicarbonitril (6), das ebenfalls durch alkalikatalysierte Umlagerung der isomeren 2,6-Diaza-Verbindung 2 entsteht. 6 läßt sich mit Salzsäure zu der entsprechenden Dicarbonsäure 9 hydrolysieren und zu 1,5-Dimethyl-2,8-diaza-cis-bicyclo-[3.3.0]octan-3,7-dion (10) decarboxylieren. Bromwasserstoffsäure überführt 6 in 1,5-Dimethyl-2,8-dioxa-cis-bicyclo[3.3.0]octan-3,7-dion (8), dessen Struktur durch einige zusätzliche Reaktionen abgesichert wird.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751081015
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  • 8
    Electronic Resource
    Electronic Resource
    Kondensation von 1,2-Diketonen mit 2-Cyanacetamid (1975)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 3262-3270 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Condensation of 1,2-Diketonew with 2-CyanacetamidePiperidine catalysis of the condensation between 1,2-diketones and 2-cyanacetamide leads to the formation of the 4,5-dialkyl(or diaryl)-5-hydroxy-2-oxo-3-pyrroline-3-carbonitriles 2a-f, which can be dehydrated to give the 5-alkyliden-derivatives 5,6, and 7,2 reacts with malononitrile in the presence of piperidine to yield the 2,6-diaza-cis-bicyclo[3.3.0]octane-3,7-diones (e.g. 8a, b, 10) and in the presence of alkali alkoxides to yield the 2,8-diaza-cis-bicyclo[3.3.0]octane-3,7-diones (e.g. 9a, b, 11, 12). Other malonic acid derivatives add 2a to form the bicyclic compounds 13, 14 and 15.
    Notes: Die Kondensation von 1,2-Diketonen mit 2-Cyanacetamid unter Piperidin-Katalyse führt zu den 4,5-Dialkyl(oder Diaryl)-5-hydroxy-2-oxo-3-pyrrolin-3-carbonitrilen 2a-f, die unter Dehydratisierung in die 5-Alkyliden-Derivate 5,6 und 7 übergehen können. 2 reagiert mit Malononitril in Gegenwart von Piperidin zu den 2,6-Diaza-cis-bicyclo[3.3.0]octan-3,7-dionen (z. B. 8a, b, 10) und in Gegenwart von Alkalialkoholat zu den 2,8-Diaza-cis-bicyclo[3.3.0]octan-3,7-dionen (z. B. 9a, b, 11, 12). Mit anderen Malonsäurederivaten wurden aus 2a die Bicyclen 13, 14 und 15 erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19751081016
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  • 9
    Electronic Resource
    Electronic Resource
    6-Alkyl- und Aryl-1,2,3,4-tetrachlorfulvene (1976)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 3929-3938 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 6-Alkyl- and 6-Aryl-1,2,3,4-tetrachlorofulvenesCondensation of 1,2,3,4-tetrachloro-1,3-cyclopentadiene (2) with the azomethines 3 in toluene at - 70°C or with the iminium salts 7 in tetrahydrofuran at 20 - 70oC leads to the formation of 6-alkyl- and 6-aryl-1,2,3,4-tetrachlorofulvenes 6. By acid or base catalysis the fulvenes 6 are isomerised partially to yield the 1,2,3,4-tetrachloro-5-vinylcyclopentadienes 8. At room temperature the equilibrated mixture contains for 6g 100% 8, for 6f 60%8 and 40% 6f for 6c 10% 8 and 90% 6c, and for 6b 100% 6b.
    Notes: Die Kondensation des 1,2,3,4-Tetrachlor-1,3-cyclopentadiens (2) mit den Azomethinen 3 in Toluol bei - 70oC oder mit den Iminiumsalzen 7 in Tetrahydrofuran bie 20 - 70°C liefert die 6-Alkyl- und 6-Aryl-1,2,3,4-tetrachlorfulvene 6. Unter Säure- oder Basen-Katalyse isomerisieren die Fulvene 6 teilweise zu den, 1,2,3,4-Tetrachlor-5-vinycyclopentadienen 8. Das Gleichgewichtsgemische besteht bei Raumtemperatur für 6g aus 100% 8, für 6f aus 60% 8 und 40% 6f, für 6c aus 10% 8 und 90% 6c und für 6b aus 100% 6b.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19761091221
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  • 10
    Electronic Resource
    Electronic Resource
    Thiocarbonyl-Ylide des 1,3-Diazacyclopentadiens und des Cyclopentadiens (1978)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 272-281 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiocarbonyl Ylides of 1,3-Diazacyclopentadiene and of CyclopentadieneThe reaction of the thioureas 10 with 4,5-dicyano-2-diazo-2H-imidazole (11) leads to elimination of nitrogen with formation of the isothiuronium S-4,5-dicyano-2-imidazolides 8. At 0°C the isothiuronium S-azo(4,5-dicyano-2-imidazolides) 12 can be isolated as labile intermediates. In a similar way the thioureas 10 combine with the phenyliodonium tricyanocyclopentadienides 17 and 19 to give the isothiuronium S-tricyanocyclopentadienides 18 and 20, respectively. The spectroscopic data indicate that the thermically very stable thiocarbonyl ylides 8, 18, and 20 should be correctly formulated as betaines.
    Notes: Die Thioharnstoffe 10 reagieren mit 4,5-Dicyan-2-diazo-2H-imidazol (11) unter Stickstoff-Eliminierung zu den Isothiuronium-S-4,5-dicyan-2-imidazoliden 8. Bei 0°C läßt sich die labile Reaktionszwischenstufe in Form der Isothiuronium-S-azo(4,5-dicyan-2-imidazolide) 12 abfangen. In analoger Weise setzen sich die Thioharnstoffe 10 mit den Phenyliodonium-tricyancyclopentadieniden 17 und 19 zu den Isothiuronium-S-tricyancyclopentadieniden 18 und 20 um. Auf Grund der spektroskopischen Daten sind die thermisch sehr stabilen Thiocarbonyl-Ylide 8, 18 und 20 als Betaine zu formulieren.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19781110126
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