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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 1015-1026 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Aminoethynyl)metallation, VIII. Reactions of β-Silylated Ynamines with Ketene; Competition of (Aminoethynyl)silylation and [2 + 2]-CycloadditionSilylethynyl)amines 1 react with ketene (2) to yield according to the principle of the [2 + 2]-cycloaddition preferentially the 2-silyl-2,3-butadienamides 6 and the 3-amino-2-silyl-2-cyclobuten-1-ones. 7. The latter ones hydrolyze easily to the corresponding silyl-free cyclobutenones 8. In some cases one can isolate besides these compounds (see the reactions of 1a and 1e) or exclusively (see the reaction of 1d) 1:2-and 1:3-adducts, the formation of which can be explained via the non detectable (3-siloxy-3-buten-1-ynyl)amines 4 [“(aminoethynyl)silylation”]. These enynamines add to their C/C triple bond a second molecule of ketene (2) to give the allene carboxamides (see 5d) and cyclobutenones 9. The compounds 9 easily hydrolyze to the corresponding acetylcyclobutenones 10 and they react with exceeding ketene (2) to form the 1:3-adducts 11. The cyclobutenone 9d isolable in substance adds diphenyl ketene and tert-butylcyanoketene in the same way to give the analogous chain prolongation products 14 and 15.
    Notes: (Silylethinyl)amine 1 reagieren mit Keten (2) bevorzugt nach dem Prinzip der [2 + 2]-Cycloaddition zu 2-Silyl-2,3-butadienamiden 6 und zu 3-Amino-2-silyl-2-cyclobuten-1-onen 7. Letztere hydrolysieren leicht zu den entsprechenden silylfreien Cyclobutenonen 8. In einigen Fällen isoliert man zusätzlich (s. Umsetzung von 1a und 1e) oder ausschließlich (s. Umsetzung von 1d) 1:2-und 1:3-Addukte, deren Bildung über die hier nicht nachweisbaren (3-Siloxy-3-buten-1-inyl)amine 4 erklärt wird [„(Aminoethinyl)silylierung“]. Diese Eninamine addieren an ihre C/C-Dreifachbindung ein weiteres Ketenmolekül zu entsprechend substituierten Allencarboxamiden (s. 5d) und Cyclobutenonen 9. Die Verbindungen 9 hydrolysieren leicht zu den entsprechenden Acetylcyclobutenonen 10 und reagieren mit überschüssigem Keten (2) zu den 1:3-Addukten 11 weiter. Das in Substanz isolierbare Cyclobutenon 9d addiert in gleicher Weise Diphenylketen bzw. tert-Butylcyanketen zu analogen Kettenverlängerungsprodukten 14 bzw. 15.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1953-1963 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloadditions, 6. Intramolecular Diels-Alder Reaction of Allenecarboxanilides; Variation of the Residue Geminal to the Carboxamide GroupThe 2,3-butadienanilides 6a-h, unsubstituted in the ω-position, are synthesized by the ynamine way and submitted to thermolysis. They isomerize without exception by intramolecular Diels-Alder reaction more or less quickly, irreversibly, and quantitatively to give the tricyclic lactams 8a-h, the aniline nucleus functioning as diene in all cases. The structures of 8 are confirmed by spectroscopic data and by an X-ray analysis (8b).
    Notes: Die in ω-Position unsubstituierten 2,3-Butadienanilide 6a-h werden auf dem Inaminweg synthetisiert und der Thermolyse unterworfen. Sie isomerisieren ohne Ausnahme in einer intramolekularen Diels-Alder-Reaktion mehr oder weniger rasch, irreversibel und quantitativ zu den tricyclischen Lactamen 8a-h, wobei der Anilinkern jeweils als „Dien“ fungiert. Die Strukturen 8 werden spektroskopisch und durch eine Röntgenstrukturanalyse (8b) bestätigt.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1358-1366 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloadditions, III. - Reactions of Ynamines with SilylketenesThe ynamines 1a-e react with the silyl aldoketenes 2a and b in a normal way under [2+2] cycloaddition to give the allenecarboxamides 6 and in one case a cyclobutenone derivative. The presence of the silyl group in the adducts gives rise to 1,3-migrations of the geminal hydrogen atom, which transform the primarily formed cyclobutenone 4d into the isolated derivative 7d and a part of the allenes 6 into the isomeric silylacetylenes 8. The tricyclic lactam 10 is formed in low yield during the distillation of 4-(dimethylphenylsilyl)-N,2-dimethyl-2,3-butadienanilide (6c); its formation is caused by an intramolecular Diels-Alder reaction between the aniline nucleus and the second allenic double bond.
    Notes: Die Inamine 1a-e reagieren mit den Silylaldoketenen 2a und b in der üblichen Weise unter [2+2]-Cycloaddition zu den Allencarboxamiden 6 und in einem Fall zu einen. Cyclobutenonderivat. Verursacht durch die Anwesenheit der Silylgruppe in den Addukten, treten 1,3-Verschiebungen des zur Silylgruppe geminal-ständigen Wasserstoffatoms auf, die das Cyclobutenon 4d in das isolierte Derivat 7d und ein Teil der Allene in die isomeren Silylacetylene 8 umwandeln. Bei der Destillation von 4-(Dimethylphenylsilyl)-N,2-dimethyl-2,3-butadienanilid (6c) wird in geringer Ausbeute das tricyclische Lactam 10 isoliert, dessen Bildung durch eine intramolekulare Diels-Alder-Reaktion zwischen dem Anilinkern und der zweiten allenischen Doppelbindung verursacht wird.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1987 (1987), S. 771-776 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Aminoethynyl) Metallations, 18. - Reactions of (Stannylethynyl) and (Silylethynyl) Ethers with Acylketenes(Stannylethynyl) ethers 1 react with tert-butylcyanoketene (2) to give the (stannyloxyvinyl)yne ethers 4. Reaction with an educt ratio of 1:2 furnishes via the primarily formed zwitterion 3 (≙ 1,4-dipole) the dioxine derivatives 6 which lose their stannyl groups by hydrolysis to give the bis(alkylidene)-1,3-dioxines 7. Analogously 2 reacts with the N-ethynylanilines 8 to give the 1,3-dioxine derivatives 13. (Stannylethynyl) ethers 1 and also (silylethynyl) ethers 15 react with the acylketenes 16 and 17 by [4 + 2] cycloaddition to furnish the 4-pyrones 18 and 19.
    Notes: (Stannylethinyl)ether 1 reagieren mit tert-Butylcyanketen (2) unter Bildung der (Stannyloxyvinyl)inether 4. Umsetzung im Verhältnis 1:2 führt über das primäre Zwitterion 3 (≙ 1,4-Dipol) zu den Dioxinderivaten 6, die unter Stannylabspaltung die Bis(alkyliden)-1,3-dioxine 7 liefern. Analog reagiert 2 mit den N-Ethinylanilinen 8 zu den 1,3-Dioxinderivaten 13. Mit den Acylketenen 16 und 17 reagieren die (Stannylethinyl)- und (Silylethinyl)ether 1 bzw. 15 unter [4 + 2]-Cycloaddition zu den 4-Pyronen 18 und 19.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1987 (1987), S. 381-383 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Aminoethynyl) Metalations, 17. - Reactions of (Silyl-, Germyl-, and Stannylethynyl)amines with Diethyl CarbonylmalonateThe metalated ynamines 1a-i react with diethyl carbonylmalonate (2) to yield the 4-pyrones 5a-i. The formation of these [4 + 2] cycloadducts is assumed to be accompanied or even preceded by aminoethynyl metalation giving the enynamines 4. Under hydrolytic conditions in 5 either only the organyl moiety is extruded (see formation of 7) or in addition the ketene acetal structure is hydrolyzed whereby 4-hydroxy-2-pyrones 8 are formed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 94 (1982), S. 631-632 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract.Das vollständige Manuskript dieser Zuschrift erscheint in: Angew. Chem. Suppl. 1982, 1473-1478
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2430-2443 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloadditions, 7. Intramolecular Diels-Alder Reactions of Allenecarboxanilides; Variation of the Substituents in the p-Position of the Aniline NucleusThe N-methyl-1,2-propadiene-1-carboxanilides 6a-h, differently substituted in the p-position, are synthesized by Wittig reaction of the carbamoylmethylenephosphoranes 5 with ketene. They isomerize by thermolysis in boiling xylene to give the tricycles 7a-h, the products of the intramolecular Diels-Alder reaction, and in some cases also to the quinolones 9, the products of a cyclization reaction. The order of the reaction and the influence of the substituents upon the rate of the intramolecular Diels-Alder reaction are determined by 1H NMR spectroscopy.
    Notes: Die in p-Position verschieden substituierten N-Methyl-1,2-propadien-1-carboxanilide 6a-h werden durch Wittig-Reaktion der Carbamoylmethylenphosphorane 5 mit Keten erzeugt. Sie isomerisieren bei der Thermolyse in siedendem Xylol in einer intramolekularen Diels-Alder-Reaktion zu den Tricyclen 7a-h, teilweise aber auch unter Cyclisierung zu den Chinolonen 9. Reaktionsordnung und der Einfluß der Substituenten auf die Geschwindigkeit der intramolekularen Diels-Alder-Reaktion werden 1H-NMR-spektroskopisch bestimmt.
    Additional Material: 8 Tab.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 21 (1982), S. 620-620 
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract.The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1473. DOI:10.1002/anie.198214730
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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