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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 740-752 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Physical Properties of Mesoionic 1,3-Dithiolones1)1,3-Dithiolylium-4-olates 3a-1 are preparatively interesting mesoionic 6π Arenes. Their synthesis from the corresponding dithioester derivatives 1a-1 and their infrared, electronic, and mass spectra are described. 3a, b, and f possess as sydnone analogues compounds relatively high dipole moments of 5.00, 5.54, and 5.98 D, respectively.
    Notes: 1,3-Dithiolylium-4-olate 3a-1 sind präparativ interessante mesoionische 6π-Aromaten. Ihre Synthese aus den entsprechenden Dithiocarbonester-Derivaten 1a-1 sowie Infrarot-, Elektronen- und Massenspektren werden beschrieben. Als Sydnon-Analoga besitzen 3a, b und f relativ große elektrische Momente von 5.00, 5.54 bzw. 5.98 D.
    Additional Material: 1 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 3029-3036 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [3 + 2]Cycloaddition Reactions of Mesoionic 1,3-Dithiolones to Ethylenedicarboxylic Acid Derivatives and 1,2-DibenzoylethyleneAs cyclic thiocarbonyl ylid the 1,3-dithiolylium-4-olate 1a combines across the 2,5-position with N-phenyl maleoylimide with formation of the endo/exo isomeric 2,7-dithiabicyclo[2.2.1]heptan-3-one derivatives in 98% yield. 1a reacts with maleic anhydride to produce 6. The analogous reactions of the mesoionic dithiolones 1a-d with dimethyl maleate proceed with formation of the endo-adducts 10a-d. Furthermore, 1a reacts with dimethyl fumarate or cis- or trans-dibenzoylethylene to produce 11a, 12a or 11b, 12b, respectively. The adduct structures are consistent with spectroscopic data and the results of chemical reactions.
    Notes: Als cyclisches Thiocarbonyl-ylid vereinigt sich das 1,3-Dithiolylium-4-olat 1a in 2,5-Stellung mit N-Phenylmaleinimid unter Bildung der endo exo-isomeren 2,7-Dithiabicyclo[2.2.1]heptan-3-on-Derivate 2,3 in 98 proz. Ausbeute. Mit Maleinsäureanhydrid reagiert 1a zu 6. Die analogen Umsetzungen der mesoionischen Dithiolone 1a-d mit Maleinsäure-dimethylester führen zu den endo-Addukten 10a-d. Weiterhin reagiert 1a mit Fumarsäure-dimethylester bzw. cis- oder trans-Dibenzoylethylen zu 11a, 12a bzw. 11b, 12b. Spektroskopische Daten und die Ergebnisse chemischer Abbaureaktionen sind in Übereinstimmung mit den Addukt-Konstitutionen.
    Additional Material: 1 Tab.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 753-760 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Preparative Entry to Thiophene Derivatives by Way of Thermal [3 + 2] Cycloaddition Reactions of Mesoionic 1,3-Dithiolones to AlkynesAs cyclic thiocarbonyl ylids the 1,3-dithiolylium-4-olats 1a-jcombine in 2,5-position at 90-130°C with dimethyl acetylenedicarboxylate with formation of non-isolable primary adducts of type 2. The latter fragment with fast evolution of carbon oxisulfide to give the thiophene diesters 3a, b, d, f, h-j in 67-100% yield. The analogous cycloaddition reactions of 1a with propiolic ester, phenylpropiolic ester, acetyl phenylacetylene, benzoyl phenylacetylene and phenylacetylene yield the thiophene derivatives 6-10.
    Notes: Die 1,3-Dithiolylium-4-olate 1a-j nehmen als cyclische Thiocarbonyl-ylide in 2.5-Stellung bei 90-130°C Acetylendicarbonester unter Bildung nicht isolierbarer Primäraddukte vom Typ 2 auf. Diese zerfallen rasch unter Kohlenoxysulfid-Abspaltung in 67-100proz. Ausbeute zu den Thiophen-dicarbonestern 3a, b, d, f, h-j. Die analogen Cycloadditionen von 1a an Propiolester, Phenylpropiolester, Acetylphenylacetylen, Benzolylphenylacetylen bzw. Phenylacetylen ergeben die Thiophen-Derivate 6-10.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 3037-3047 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of Mesoionic 1,3-Dithiolones to Cyclic Olefin DerivativesThe 1,3-dithiolylium-4-olate 1a reacts with 1,2,3-triphenylcyclopropene at 100°C with formation of the isomeric free exo-tricycle 2a in 88% yield; oxidation converts 2a to the sulfoxides 3 and 4. At 100°C methyl 1,2-diphenylcyclopropene-3-carboxylate combines with 1a to produce 2b (88%), whereas cyclopropene reacts with 1a, b at room temperature with formation of the 1:1 cycloadducts 2c, d. From 1a, c and acenaphthylene one obtains 5a or 5b, respectively. On the other hand, the reactions of 1a or 1d with excess p-benzoquinone yield in addition to the 1:1-adducts 7a, b the thiophene derivatives 9a, b which result from dehydrogenation and fragmentation. By analogous reactions of 1a or 1c with norborne, norbornadiene or norbornene-5,6-dicarboxylic ester the tetracyclic adducts 10, 12a or 12b are formed, respectively. Furthermore, 1a undergoes cycloaddition with cyclopentene, cyclopentadiene, 1,3-cyclohexadiene, and 1,5-cyclooctadiene with formation of the heterotricycles 13-16, 18a, b.Spectroscopic data and the results of chemical reactions are in agreement with the structures of the new adducts.
    Notes: Das 1,3-Dithiolylium-4-olat 1a reagiert mit 1,2,3-Triphenylcyclopropen bei 100°C in 88proz. Ausbeute zum isomerenfreien exo-Tricyclus 2a, der durch Oxidation in die Sulfoxide 3 und 4 übergeht. Mit 1,2-Diphenylcyclopropen-3-carbonester vereinigt sich 1a bei 100°C zu 2b (88%), während Cyclopropen bereits bei Raumtemp. mit 1a, b die 1:1-Cycloaddukte 2c, d bildet. Aus 1a, c und Acenaphthylen erhält man 5a bzw. 5b. Andererseits liefern die Reaktionen von 1a bzw. 1d mit überschüssigem p-Benzochinon neben den 1:1-Addukten 7a, b noch die Thiophen-Derivate 9a, b als Ergebnis einer dehydrierenden Fragmentierung. Durch entsprechende Umsetzungen von 1c bzw. 1a mit Norbornadien, Norbornen oder Norbornen-5,6-dicarbonester gelangt man zu den tetracyclischen Addukten 10, 12a bzw. 12b. Weiterhin cycloaddiert 1a an Cyclopenten, Cyclopentadien, 1,3-Cyclohexadien und 1,5-Cyclooctadien unter Bildung der Heterotricyclen 13-16, 18a, b.Spektroskopische Daten und die Ergebnisse chemischer Überführungsreaktionen sind in Einklang mit den Strukturen der neuen Addukte.
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  • 5
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Regioselectivity of the [3 + 2]-Cycloaddition Reactions of Mesoionic 1,3-Dithiolones to Electron-poor and Electron-rich AlkenesAs cyclic thiocarbonyl ylides the 1,3-dithiolylium-4-olates 1a, b combine in 2,5-position with styrene to form the 2,7-dithiabicyclo[2.2.1]heptan-3-one derivatives 2a, b, which contain the phenyl group in the 6-endo-position. 1a reacts with α-methylstyrene to give 2c in 74% yield. The reactions of 1a or 1e with the electron-poor C=C bond of methyl acrylate proceed with formation of mixtures of both positionally isomeric [1:1]-adducts 4a, b (64:36) or 4c, d (82:18), respectively. Furthermore, the cycloaddition reactions of 1 with acrylonitrile, methyl cinnamate, ethylenetetracarbonitrile, tetramethylethylene, ethyl vinyl ether, cyclohexyl vinyl ether, 1-cyclopentenyl ethyl ether, ethyl 1-isobutenyl ether, and N-(1-isobutenyl)morpholine are described. The observed regioselectivities are qualitatively discussed on the basis of MO-perturbation theory.
    Notes: Die 1,3-Dithiolylium-4-olate 1a, b nehmen als cyclische Thiocarbonyl-ylide in 2,5-Stellung Styrol auf unter Bildung der 2,7-Dithiabicyclo[2.2.1]heptan-3-on-Derivate 2a, b mit dem Phenylrest in der 6-endo-Stellung. Mit α-Methylstyrol vereinigt sich 1a in 74proz. Ausbeute zu 2c. Die Umsetzungen von 1a und 1e mit der elektronenarmen C=C-Bindung des Acrylsäure-methylesters lie-fern dagegen Gemische beider stellungsisomeren [1:1]-Addukte 4a, b (64:36) bzw. 4c, d (82:18). Weiterhin werden Cycloadditionen von 1 an Acrylonitril, Zimtsäure-methylester, Ethylentetra-carbonitril, Tetramethylethylen, Ethylvinylether, Cyclohexylvinylether, 1-Cyclopentenylethyl-ether, Ethyl-1-isobutenylether und N-(1-Isobutenyl)morpholin beschrieben. Die beobachteten Regioselektivitäten werden qualitativ mit Hilfe der MO-Störungstheorie diskutiert.
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  • 6
    Publication Date: 1968-01-01
    Print ISSN: 0040-4039
    Electronic ISSN: 1873-3581
    Topics: Chemistry and Pharmacology
    Published by Elsevier
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  • 7
    Publication Date: 1968-01-01
    Print ISSN: 0040-4039
    Electronic ISSN: 1873-3581
    Topics: Chemistry and Pharmacology
    Published by Elsevier
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  • 8
    Publication Date: 1968-01-01
    Print ISSN: 0040-4039
    Electronic ISSN: 1873-3581
    Topics: Chemistry and Pharmacology
    Published by Elsevier
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