Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1980-1984  (4)
Source
Material
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Enamines. 8. Polarographic study of the reactions of a number of enamino ketones with nucleophilic reagents (1981)
    Springer
    Chemistry of heterocyclic compounds 17 (1981), S. 256-260 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The hydrolysis and hydrazinolysis of cyclic enamino ketones of the pyrrolidine, piperidine, and hexahydroazepine series, as well as their noncyclic analogs, were investigated. It is shown that these processes have several principles in common. A bell-shaped dependence of kobs on the pH of the medium is characteristic for hydrolysis; the reaction of the enamino ketones with hydrazine hydrate in absolute ethanol is accelerated in the presence of p-toluenesulfonic acid. It is shown that the rates of hydrolysis and hydrazinolysis depend on the size of the saturated azaheteroring and change in the order 6 〉 5 〉 7. A possible mechanism for the processes in which the slow step is C-protonation and(or) attack by the nucleophilic reagent in the “enamine” α position is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505989
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Enamines. 9. Polarographic reduction of enamino ketones in aqueous media (1981)
    Springer
    Chemistry of heterocyclic compounds 17 (1981), S. 261-267 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The mechanism of the polarographic reduction of cyclic enamino ketones of the pyrrolidine, piperidine, and hexahydroazepine series of two types, viz., compounds in which the α-carbon atom of the enamine is included in the azoheteroring, and enamino ketones in which the double bond is located outside the cyclic system, was investigated. The acyclic analogs were also studied. It is shown that the two- or four-electron reduction depends substantially on the structures of the investigated compounds and the pH of the medium; this in turn is associated with a change in the character, rate, and site of protonation of the enamino ketones and the compounds formed as a result of their reduction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505990
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Lactam acetals and acid amides. 31. Synthesis, protonation, and basicities of some heterocyclic enamino ketones (1980)
    Springer
    Chemistry of heterocyclic compounds 16 (1980), S. 256-260 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The protonation of cyclic enamino ketones of the pyrrolidine, piperidine, and hexahydroazepine series, as well as their noncyclic analogs, was studied by PMR spectroscopy. It is shown that the presence of a CH2 or CH3 group in the “enamine” position leads to C protonation (in CF3COOH). In the case of enamino ketones that do not contain substituents in the “enamine” α position N-and O-protonated forms are observed in CF3COOH. The measured pKa values (in 10% alcohol) and the ΔpKa values (in nitromethane) of the enamino ketones show that the compounds for which C protonation is characteristic are two to three orders of magnitude more basic than in the case of compounds that do not contain substituents in the “enamine” α position; this is explained by the different character of protonation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02401722
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Lactam acetals and acid amides. 31. Synthesis, protonation, and basicities of some heterocyclic enamino ketones (1980)
    Springer
    Chemistry of heterocyclic compounds 16 (1980), S. 256-260 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The protonation of cyclic enamino ketones of the pyrrolidine, piperidine, and hexahydroazepine series, as well as their noncyclic analogs, was studied by PMR spectroscopy. It is shown that the presence of a CH2 or CH3 group in the “enamine” position leads to C protonation (in CF3COOH). In the case of enamino ketones that do not contain substituents in the “enamine” α position N-and O-protonated forms are observed in CF3COOH. The measured pKa values (in 10% alcohol) and the ΔpKa values (in nitromethane) of the enamino ketones show that the compounds for which C protonation is characteristic are two to three orders of magnitude more basic than in the case of compounds that do not contain substituents in the “enamine” α position; this is explained by the different character of protonation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00553889
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...