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  • 1
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 2965-2980 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Diazo Compounds and Azides, XLII. (Diazomethyl)cyclopropenes by Electrophilic Diazoalkane SubstitutionThe (diazomethyl)cyclopropenes 9 and 10 are formed via electrophilic diazoalkane substitution preferably of diazomethylphosphoryl compounds with cyclopropenylium salts. Either the diazomethyl compounds (7a-c) react with the cyclopropenylium salts 6a-e in the presence of triethylamine (method A) or the metallated diazo compounds 8a-d are combined with the cyclopropenylium bromides 6c-e (method B) (details see table 1). The (diazomethyl)cyclopropenes undergo a novel type of isomerization to pyridazines, partly without heating (9d-f → 11b-d), partly by refluxing in toluene (9a,g → 11a,e as well as 10e,f → 12a,b). The bicyclic betaines 15 and 17 are supposed to be intermediates. The diazomethyl compounds 9a and b yield the α,β- unsaturated ketones 20a and b by acid-catalyzed decomposition.
    Notes: Die (Diazomethyl)cyclopropene 9 und 10 entstehen durch elektrophile Substitution vorzugsweise von Diazomethylphosphorylverbindungen mit Cyclopropenyliumsalzen. Man setzt entweder die Diazomethylverbindungen selbst (7a-c) in Gegenwart von Triethylamin mit den Cyclopropenyliumsalzen 6a-e um (Methode A) oder läßt die metallierten Diazoverbindungen 8a-d mit den Cyclopropenyliumbromiden 6c-e reagieren (Methode B) (Details s. Tab. 1). Die (Diazomethyl)-cyclopropene gehen teils ohne Erwärmen (9d-f → 11b-d), teils beim Erhitzen in Toluol (9a,g → 11a,e sowie 10e,f → 12a,b) eine neuartige Isomerisierung zu Pyridazinen ein; Zwischenstufen sind vermutlich die bicyclischen Betaine 15 und 17. Die Diazomethylverbindungen 9a und b liefern bei der säurekatalysierten Zersetzung die α,β-ungesättigten Ketone 20a und b.
    Additional Material: 3 Tab.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1315-1328 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Diazo Compounds and Azides, LV. 7-(Diazomethyl)cycloheptatrienes by Electrophilic Diazoalkane SubstitutionThe silver-(diazomethyl)phosphoryl compounds 2a-c smoothly undergo electrophilic diazo-alkane substitution with 1 to give 3a-c. In contrast, a more complex product formation is encountered in the reaction of 1 with the mercury-bis(diazomethylcarbonyl) compounds 4a-d: Besides the 7-(diazomethyl)cycloheptatrienes 5a-d the styrene derivatives 6a-c as well as the bromomercurio compounds 7a-b are formed. Probably the norcaradiene intermediates 12 and 14 play a role in the formation of 6 and 7. The reaction of the 7-(diazomethyl)cycloheptatrienes 3a-c and 5a, b, d with PTAD (16) affords the [4 + 2]-cycloadducts 17a-f, derived from 7-(diazomethyl)norcaradiene isomers. The structures of 3, 5, and 17 are based above all on 1H and 13C NMR spectroscopic investigations.
    Notes: Die Silber-(diazomethylphosphoryl)-Verbindungen 2a-c gehen mit 1 glatt elektrophile Diazoalkansubstitution zu 3a-c ein. Im Gegensatz dazu begegnet man einem komplexeren Produktbild bei der Umsetzung von 1 mit den Quecksilber-bis(diazomethylcarbonyl)-Verbindungen 4a-d: Neben den 7-(Diazomethyl)cycloheptatriene 5a-d werden die Styrolderivate 6a-c sowie die Brommercurioverbindungen 7a-d gebildet. Die Norcaradienzwischenstufen 12 und 14 spielen vermutlich eine Rolle bei der Bildung von 6 und 7. Mit PTAD (16) liefern die 7-(Diazomethyl)cycloheptatriene 3a-c und 5a, b, d von Norcaradienisomeren abgeleiteten [4 + 2]-Cycloaddukte 17a-f. Die Strukturen von 3, 5 und 17 werden vor allem durch 1H und 13C-NMR-spektroskopische Untersuchungen ermittelt.
    Additional Material: 6 Tab.
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  • 4
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Investigations on Diazo Compounds and Azides, XXXII. - Substitution Reactions at the Diazo Carbon of Diazomethylphosphoryl Compounds
    Additional Material: 6 Tab.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1992 (1992), S. 799-802 
    ISSN: 0170-2041
    Keywords: Sialic acids ; Phase-transfer catalysis ; N-Ketosides ; Carbohydrates ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α-N-Ketosides of N-acetylneuraminic acid (Neu5Ac) can be synthesized by using azide and thiocyanate salt as aglycone under conditions of phase-transfer catalysis (PTC). The catalytic hydrogenation of the 2-α-azido ketoside 3 leads to the 2-α-amino ketoside 4 in good yield. This 2-α-amino ketoside 4 can be transformed into the 2-α-acetamido ketoside 5 and the 2-α-benzoylamido ketoside 6. Zemplén deacetylation and saponification give the corresponding 2-N-acyl ketosides 7 and 8, which cannot be hydrolyzed by neuraminidase (Clostridium perfringens). Treatment of the 2-α-amino ketoside 4 with p-nitrobenzaldehyde results in the formation of p-nitrobenzylideneamine 9. Based on the strict stereoselectivity of the PTC glycosidation reaction with sialic acid derivatives and the exclusive formation of the N-ketoside 10 in the reaction with potassium thiocyanate, a model of the mechanism of the PTC glycosidation procedure with sialic acid derivatives has been evaluated.
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  • 6
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Diazo Compounds and Azides, XXXV. Acylation of Diazomethylphosphoryl and Diazomethylcarbonyl Compounds with Acyl Isocyanates and IsothiocyanatesThe aroyl isocyanates 7a - c react with the diazomethylphosphoryl compounds 8a - d with formation of the phosphorylated diazoacetamides 9a, b and d - j as well as 1,3-oxazolin-4-ones 10b - j. The reaction of chlorosulfonyl isocyanate (13) with 8a, c, e and f proceeds via exclusive acylation to give the diazo compounds 14a - d, the chlorosulfonyl group of which allows further transformations with protic nucleophiles (products 12, and 16); the chlorosulfonyl group may be cleaved hydrolytically too (product 15). Reactions with tosyl isocyanate demonstrate the limits of the acylation procedure: whereas formation of the diazoalkane 19a is still observed in the case of 8a only the hydantoin derivative 21 can be isolated with 8e. The reaction of the acyl isothiocyanates 22a - e with 8a - f proceeds entirely as an acylation, yielding the 1,2,3-thiadiazoles 23a - m which represent cyclic isomers of corresponding α-diazothiocarbonyl compounds. In two cases 1,3-oxazoles (viz. 24a and b) were also obtained. Diazonium betaines of the type 4 play a key role in the interpretation of the results.
    Notes: Die Aroylisocyanate 7a - c reagieren mit den Diazomethylphosphorylverbindungen 8a - d unter Bildung der phosphorylierten Diazoacetamide 9a, b und d - j sowie der 1,3-Oxazolin-4-one 10b - j. Bei der Umsetzung von Chlorsulfonylisocyanat (13) mit 8a, c, e und f erfolgt ausschließ-lich Acylierung zu den Diazoverbindungen 14a - d, deren Chlorsulfonylgruppe weitere Reaktio-nen mit protischen Nukleophilen erlaubt (Produkte 12 und 16); sie kann auch hydrolytisch abge-spalten werden (Produkt 15). Reaktionen von Tosylisocyanat zeigen die Grenzen der Acylierungs-methode auf: Mit 8a beobachtet man noch die Bildung des Diazoalkans 19a, mit 8e läßt sich nur noch das Hydantoinderivat 21 isolieren. Die Acylisothiocyanate 22a - e liefern mit 8a - f ganz im Sinne der Acylierung die 1,2,3-Thiadiazole 23a - m, die cyclische Isomere entsprechender α-Diazothiocarbonylverbindungen darstellen. In zwei Fällen wurden zusätzlich 1,3-Oxazole (nämlich 24a und b) erhalten.  -  Diazoniumbetaine vom Typ 4 spielen eine Schlüsselrolle bei der Interpretation der Ergebnisse.
    Additional Material: 5 Tab.
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  • 7
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Bis-[1,3-diaryl-imidazolidinylidenes-(2)] with Iso-, Isothio- or Isoselenocyanates1)Bis-[1,3-diaryl-imidazolidinylidenes-(2)] (1a-c) react with isocyanates in a ratio of 1:4 to give 2,4-dioxo-1,3,6,9-tetraaza-spiro[4,4]nonanes (3a-i). As shown in the case of 3f and g, acyl-azides may also be used for this reaction because they rearrange to isocyanates under the reaction conditions; 2-acylimino-1,3-diphenyl-imidazolidines (6a and b) are formed then as byproducts. The reaction of the electron-rich olefine 1a with aryl-azides leads to the triazenes 11a or b without loss of nitrogen. Isothio- or isoselenocyanates also undergo a 4:1-reaction with 1a to give the spiroheterocycles 13a-j. A dipole intermediate 16 could be isolated from 1a and p-nitrophenyl isocyanate. Analogous 2:1-reactions (21a and b) are found with carbamoyl-isothiocyanates. All dipoles are characterized by addition of perchloric acid (14, 19a and b) and methyl iodide (15, 20a and b) by (3 + 2 = 5)-cycloadditions (17, 18, 22a-d and 23a-d). The mechanistic aspects of the reaction of 1a with heterocumulenes and azides are discussed.
    Notes: Bis-[1.3-diaryl-imidazolidinylidene-(2)] (1a-c) reagieren mit Isocyanaten im Verhältnis 1:4 zu 2.4-Dioxo-1.3.6.9-tetraaza-spiro[4.4]nonanen (3a-i). Wie bei 3f und g gezeigt wird, lassen sich hierbei auch Acylazide einsetzen, die sich unter den Reaktionsbedingungen in Isocyanate umlagern; als Nebenprodukte treten dann 2-Acylimino-1.3-diphenyl-imidazolidine (6a und b) auf. Die Umsetzung des elektronenreichen Olefins 1a mit Arylaziden verläuft unter N2-Erhalt zu den Triazenen 11a bzw. b. Isothio- bzw. Isoselenocyanate gehen mit 1a ebenfalls eine 4:1-Umsetzung zu den Spiroheterocyclen 13a-j ein. Die Dipol-Zwischenstufe 16 aus 1a und p-Nitro-phenylisothiocyanat konnte isoliert werden; analoge 2:1-Umsetzungen (21a und b) findet man bei Carbamoylisothiocyanaten. Alle Dipole sind charakterisiert durch Addition von Perchlorsäure (14, 19a und b) und Methyljodid (15, 20a und b) sowie durch (3 + 2 = 5)-Cycloadditionen (17, 18, 22a-d und 23a-d). Die mechanistischen Aspekte der Umsetzung von 1a mit Heterokumulenen und Aziden werden diskutiert.
    Additional Material: 2 Tab.
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  • 8
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 9
    ISSN: 0044-8249
    Keywords: Eisen ; Elektrochemie ; Ferrocenophane ; Makrocyclen ; Polykationen ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 82 (1970), S. 394-395 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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