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  • 1970-1974  (23)
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Accounts of chemical research 3 (1970), S. 209-216 
    ISSN: 1520-4898
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 92 (1970), S. 4985-4987 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 96 (1974), S. 6686-6691 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1676-1683 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, 15. Preparation and Solvolysis of the Stereoisomeric 1-Bromomethylene-2-methylcyclopropanesThe stereoisomeric 1-bromomethylene-2-methylcyclopropanes (6Z and 6E) are synthesized and their solvolysis rates and products in ethanol/Water mixtures are determined. 6Z and 6E solvolyse at approximately the same rates. Both isomers yield only the rearranged products 12, 14, 16 and 18, which are formed from both isomers in the same ratio. The products as well as the kinetic data are explained by assuming the formation of the stabilized cyclopropylidenemethyl cation 7.
    Notes: Die stereoisomeren 1-Brommethylen-2-methylcyclopropane (6Z und 6E) wurden dargestellt und die Solvolysegeschwindigkeiten sowie die Produkte in Äthanol/Wasser-Gemischen bestimmt. 6Z und 6E solvolysieren dabei etwa mit gleicher Geschwindigkeit. Aus beiden Isomeren entstehen ausschließlich die umgelagerten Produkte 12, 14, 16 und 18 im gleichen Mengenverhältnis. Produktanalyse und Kinetik werden mit der Bildung des stabilisierten Cyclopropylidenmethylkations 7 erklärt.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 1465-1470 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, V. Kinetics and Solvolysis of Nonafluorobutanesulfonates („Nonaflates“)The preparation and the properties of nonafluorobutanesulfonates (“nonaflates”) 1a-6a are described. The solvolysis of the cyclic vinyl nonaflates 1a-3a, like that of the already described trifluoromethanesulfonates, leads exclusively to the corresponding ketones. The nonafluorobutanesulfonates solvolyse 1.5-2 times faster than the trifluoromethanesulfonates. Therefore the nonafluorobutanesulfonate anion is the best leaving group in solvolysis reactions hitherto reported.
    Notes: Die Darstellung und die Eigenschaften der Nonafluorbutansulfonate (“Nonaflate”) 1a-6a werden beschrieben. Die Solvolyse der cyclischen Vinyl-nonaflate 1a-3a führt wie bei den entsprechenden Trifluormethansulfonaten nur zu den Ketonen, erfolgt aber 1.5-2 mal schneller als bei den Trifluormethansulfonaten. Das Nonafluorbutansulfonat-Anion stellt damit die zur Zeit beste Abgangsgruppe bei Solvolysereaktionen dar.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 3789-3793 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, VISolvolysis of 1-Cyclononenyl- and 1-Cyclodecenyl Trifluoromethanesulfonate1-Cyclononyl- (1a, n == 7) and 1-cyclodecenyl trifluoromethanesulfonate (1a, n == 8) are prepared from the corresponding cycloalkanones and trifluoromethanesulfonic acid anhydride. The reaction products as well as the reaction rates are determined in 50 percent aqueous ethanol. 1-Cyclononenyl- and 1-cyclodecenyl trifluoromethanesulfonate give the highest solvolytic rates of all 1-cycloalkenyl trifluoromethanesulfonates investigated so far. 1a (n == 7) reacts 55 times faster, and 1a (n == 8) 20 times faster than the comparable acyclic compound, cis-1-methylpropenyl triflate (2).
    Notes: 1-Cyclononenyl- (1a, n == 7) und 1-Cyclodecenyl-trifluormethansulfonat (1a, n == 8) werden aus den entsprechenden Cycloalkanonen durch Umsetzung mit Trifluormethansulfonsäure-anhydrid dargestellt und die Solvolyseprodukte sowie die Solvolysegeschwindigkeiten in 50proz. wäßr. Åthanol bestimmt. Von den bisher untersuchten 1-Cycloalkenyl-trifluormethansulfonaten zeigen 1-Cyclononenyl- und 1-Cyclodecenyl-trifluormethansulfonat die höchsten Solvolysegeschwindigkeiten. 1a (n == 7) reagiert 55mal schneller, 1a (n == 8) 20mal schneller als die acyclische Vergleichsverbindung cis-1-Methyl-propenyltriflat (2).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 3216-3222 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, 12. Solvolysis of 1,3-Cycloheptadien-2-yl and 1,3-Cyclooctadien-2-yl Trifluoromethanesulfonate1,3-Cycloheptadien-2-yl (3b) and 1,3-Cyclooctadien-2-yl trifluoromethanesulfonate (3c) are synthesized by treating the corresponding 2-cycloalkene-1-ones with trifluoromethanesulfonic acid anhydride. The solvolysis products and rates of 3b and 3c are determined in 60% and 50% ethanol, respectively. 3b solvolyzes with about the same rate as 1-cycloheptenyl trifluoromethanesulfonate (11), 3c reacts 103 times faster than 1-cyclooctenyl trifluoromethanesulfonate (12). The higher rates of the dienyltriflates 3b and 3c are explained by an increasing stabilisation of the intermediate vinyl cations by the allylic double bond.
    Notes: 1,3-Cycloheptadien-2-yl- (3b) und 1,3-Cyclooctadien-2-yl-trifluormethansulfonat (3c) werden aus den entsprechenden 2-Cycloalken-1-onen durch Umsetzung mit Trifluormethansulfonsäure-anhydrid dargestellt und die Produkte sowie Geschwindigkeiten der Solvolyse in 60 proz. bzw. 50 proz. Wäßr. Äthanol bestimmt. 3b solvolysiert etwa. gleich schnell wie 1-Cycloheptenyltrifluormethansulfonat (11), 3c reagiert etwa 103mal schneller als 1-cyclooctenyl-trifluormethansulfonat (12). Die erhöhte Reaktionsgeschwindigkeit der Dienyltriflate 3b und 3c wird mit zunehmender Stabilisierung eines intermediären Vinylkations durch die allylständige Doppelbindung erklärt.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 421-433 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transanular Rearrangements of Cyclodecynyl Derivatives5-Cyclodecyn-1-yl P-nitrobenzoate (1c) solvolyses in aqueous ethanol with transanular participation of the triple bond about 20 times faster than cis-5-cyclodecen-1-yl p-nitrobenzoate (6). The only product of the reaction is 1-oxodecaline (5). The high tendency of rearrangement of cyclodecynyl derivatives can also be shown in various other reactions: 5-Cyclodecyn-1-ol (1b) in ethanolic hydrochloric acid is quantitatively isomerized to 5; treatment of 5-cyclodecyn-1-ylamine (1d) with nitrous acid also results in partial rearrangement to 5. 5-Cyclodecyn-1-one (4) is rearranged with mineral acids as well as with boron trifluoride to 1-oxo-4a(8a)-octaline (14). Similar experiments with 1-methyl-5-heptyn-1-yl compounds (7) are reported.
    Notes: Cyclodecin-(5)-yl-[p-nitro-benzoat] (1c) solvolysiert in wäßr. Äthanol unter transanularer Beteiligung der Dreifachbindung etwa 20mal schneller als cis-Cyclodecen-(5)-yl-[p-nitro-benzoat] (6). Als einziges Reaktionsprodukt wird 1-Oxo-decalin (5) erhalten. Die hohe Umlagerungstendenz von Cyclodecinylderivaten wird auch an verschiedenen anderen Reaktionen nachgewiesen: Cyclodecin-(5)-ol-(1) (1b) wird mit äthanol. Salzsäure quantitativ zu 5 isomerisiert, Cyclodecin-(5)-yl-amin (1d) reagiert mit salpetriger Säure unter teilweiser Umlagerung ebenfalls zu 5. Cyclodecin-(5)-on-(1) (4) wird mit Mineralsäuren sowie mit Bortrifluorid in 1-Oxo-Δ4a(8a)-octalin (14) umgelagert. Über vergleichende Versuche an 1-Methylheptin-(5)-yl-Verbindungen (7) wird berichtet.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations VIII1).  -  Solvolysis of (α-Bromobenzylidene)cyclopropane and 1-Bromo-2-phenyl-1-cyclobutene(α-Bromobenzylidene)cyclopropane (7) and 1-Bromo-2-phenyl-1-cyclobutene (8) were synthesized and their solvolysis reactions studied in different solvents. Under the conditions used compound 7 reacts preferentially to form cyclopropyl phenyl ketone (15). Compound 8 yields the same ketone 15 by rearrangement. From the solvolysis products and the relatively high reaction rates it is concluded that both bromides react via a vinyl-cation mechanism.
    Notes: (α-Brombenzyliden)cyclopropan (7) und 1-Brom-2-phenyl-1-cyclobuten (8) werden dargestellt und ihre Solvolysereaktionen in verschiedenen Lösungsmitteln untersucht. Verbindung 7 reagiert dabei bevorzugt unter Bildung von Cyclopropylphenylketon (15), aus 8 wird unter Umlagerung ebenfalls das Keton 15 erhalten. Aus den Solvolyseprodukten und den vergleichsweise hohen Solvolysegeschwindigkeiten wird geschlossen, daß beide Bromide über einen Vinylkationenmechanismus solvolysieren.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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