ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • Organic Chemistry  (136)
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Synthesis and Structure of Tetraaryl Orthocarbonates from carbonimidic acid esters (1992)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 334 (1992), S. 95-97 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19923340120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Radikalreaktion an N-Heterocyclen. XIII. Oxidation cyclischer Hydrazoverbindungen mit 2,4,6-Tri-tert-butyl-phenoxyl und Folgereaktionen der Radikalkombinationsprodukte (1994)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 336 (1994), S. 350-354 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Free Radical Reactions of N-Heterocyclic Compounds. XIII. Oxidation of Cyclic Hydrazo Compounds with 2,4,6-Tri-tert-butyl-phenoxy Radical and Reactions of Radical Combination ProductsN-Heterocyclic compounds 1a, b containing the hydrazo structure were oxidized with 2,4,6-tri-tert-butyl-phenoxy radical (2). It was shown that the oxidation did not lead to the azo compounds 5a, b, but rather to radical combination products 6a, b of 2 via the intermediate hydrazyls 4a, b. The decomposition of adducts 6a, b was found to be similar to the reaction of radical combination products of aryl hydrazyls and CH-acidic compounds. The main reactions consisted of cleavage to starting radicals or elimination of isobutene forming the respective phenolic compounds 13a-c.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19943360414
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Radikalreaktionen an N-Heterocyclen. XI. ESR-spektroskopischer Nachweis von Radikalen der 3-Methyl-pyrazolin-5-one (1993)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 335 (1993), S. 435-438 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Free Radical Reactions of N-Heterocyclic Compounds. XI. ESR-Study of Radicals of 3-Methyl-pyrazolin-5-onesThe oxidation of 1,4-substituted 3-methylpyrazolin-5-ones (1a - p) led to pyrazolinonyl radicals (2a - p), which were detected directly or after trapping with nitrosobenzene as phenyl nitroxides. In a few cases, the products of oxidation of pyrazolin-5-ones (1) with electron-withdrawing groups in 4-position by peroxy radicals were endo cyclic nitroxides (8), which were also detected by ESR spectroscopy.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19933350507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Macrocyclic (1,3)- and (1,4)-benzena-(1,4)-piperazinacyclophanes (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 1515-1519 
    Details
    ISSN: 0947-3440
    Keywords: Macrocycles ; Recognition ; Piperazines ; Self-assembly ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New large, up to 45-membered macrocycles were synthesised from piperazine and m- and p-2,6-bis(bromomethyl)xylene under high dilution conditions. X-ray structures of compounds 3a, 4a, 5a, and 8b were determined. Surprisingly, none of the macrocycles prepared showed any inclusion properties towards small guest molecules. Instead, the compounds were found to self-organize during the packing process into larger structures due to the complementary of the molecular skeletons. In the crystalline state 3a forms nets, where the macrocycles are bound by H—C—H…N interactions to each other. 4a exits in a dimeric structure, which, in turn, further extends to a sheet structure. The positively charged phane 8b (di-dihydrochloride salt) adopts a chair-chair conformation, confirming that protonation of the N atoms does not change the conformation.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1995199508207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Molecular switches: Calculations on the stereodivergent hetero Diels-Alder reaction of chiral 1-oxa-1,3-butadienes with different lewis acids (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 1921-1924 
    Details
    ISSN: 0947-3440
    Keywords: Calculations, semiempirical ; Lewis acid ; Conformation ; Hetero Diels-Alder reaction ; Facial selectivity ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The stereodivergent facial differentiation of the intermolecular hetero Diels-Alder reaction of the 1-oxa-1,3-butadiene 1 with 2 in the presence of trimethylsilyl trifluoromethanesulfonate (TMS-OTf) or Me2AlCl is explained on the basis of semiempirical calculations (AM1 and PM3). The oxabutadiene 9 was shown to prefer the anti arrangement of the carbonyl groups of the imide moiety in the ground state by 1.8 kcal/mol (Am1) or 2.2 kcal/mol (PM3). In the silylated compound 10 this preference is even more pronounced. In contrast, in the chelate 11 the imide moiety is fixed in a syn conformation. The orientation of the oxazolidinone rings in 10 and 11 is opposite: thus, the absolute configuration of the cycloadducts is determined by a facial differentiation due to an asymmetric induction under chelate control (11) or nonchelate control (10).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1995199511271
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of Schiff Base Chelates of Tetramic Acids as NMR Contrast Agents for micro imaging (1996)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 338 (1996), S. 642-646 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel Cu(II) complexes derived from N,N′ P-ethylene-bis-(1′,5′,5′-trimethyltetramic acid-3′-acetiminato)copper(II) aCu [1] were evaluated as contrast agents for NMR microscopy and therefore tested for penetration into living cells (Xenopus laevis oocytes). By in vitro 1H NMR relaxation (T1) and atomic absorption spectroscopy measurements (AAS) we confirmed, that independent of the complex isomers (Z/Z, Z/E, E/E, E/Z) compounds with alkyl substituents in R1 - R5 exclusively were able to penetrate the plasma membranes. It is noteworthy that compounds containing the tetramic acid moieties from both a penetrating and a non-penetrating complex most likely were accumulated in the plasma membrane and/or plasma membrane-associated vesicles, which was concluded from in vitro NMR measurements combined with AAS trace analyses. In this context the crystal and molecular structure of the ‘chimerical’ C17H22N4O4Cu · 3H2O kCu · 3H2O were determined by x-ray analysis. The x-ray structural parameters are discussed in detail.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.199633801122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Umwandlung phenolischer α-Aminosäuren in α-Ketosäuren (1983)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1983 (1983), S. 1638-1639 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Conversion of Phenolic α-Amino Acids into α-Keto acidsA one-pot conversion of tyrosine (1a) and 3,4-dihydroxyphenylalanine (DOPA) (1b) into 3-(4-hydroxyphenyl)pyruvic acid (2a) and 3-(3,4-dihydroxyphenyl)pyruvic acid (2b), respectively, via 2-trifluoromethyl-3-oxazolin-5-ones 5 is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198319830918
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Verbindungen mit verminderten Porphin-π-Systemen: Synthese des 12,13,17,18-Tetranorporphins, der Stammverbindung der Isobakteriochlorine (1985)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1985 (1985), S. 1004-1011 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Compounds with Reduced Porphin π-Systems: Synthesis of 12,13,17,18-Tetranorporphin, the Parent Compound of the IsobacteriochlorinsFor a comparison of the properties of porphin and isobacteriophin (4a), a synthesis of 4a via the macrocyclic diamine 3a was elaborated. The copper complex 3b can be dehydrogenated with platinum oxide in refluxing toluene to give 4b. Using the same reaction conditions, isobacteriophin (4a) and its platinum complex 4c were obtained only in very poor yields. 4a, however, is accressible in 2% yield by flash vacuum-thermodehydrogenation of 3a. The UV spectrum of 4a is similar to spectra of isobacteriochlorin derivatives. From comparison of the 1H NMR spectra of 4a and octaethylisobacteriochlorin and enhanced planarity of the conjugated system may be deduced as a consequence of the removal of the ethano bridges.
    Notes: Für einen Vergleich der Eigenschaften des Porphins und des Isobakteriophins (4a) wurde dieses über das makrozyklische Diamin 3a dargestellt. Der Kupfer-Komplex 3c läßt sich mit Platinoxid in siedendem Toluol zum Kupfer-Isobakteriophin (4b) dehydrieren. Die gleiche Reaktion an 3a ergibt nur geringe Mengen des Isobakteriophins (4a) und seines Platin-Komplexes 4c, 4a wird aus 3a in 2% Ausbeute durch Thermoflash-Dehydrierung erhalten. Das UV-Spektrum von 4a weist für Isobakteriochlorine typische Banden auf. Aus einem Vergleich der 1H-NMR-Spektren von 4a und Octaethylisobakteriochlorin läßt sich eine vermehrte Planarität des Konjugationssystems beim Fortfall der Ethanobrücken ableiten.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198519850514
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Synthesen von hydroxylierten Bipyridinen, II. 3,4′-Dihydroxy-2,3′-bipyridin (1987)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1987 (1987), S. 1123-1124 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of Hydroxylated Bipyridines, II. - 3,4′-Dihydroxy-2,3′-bipyridineThe title compound 1 is obtained by coupling of 2-iodo-3-methoxypyridine (3) and 3-bromo-4-methoxypyridine (4) with Nickel(0) - to yield the dimethyl ether 2 (plus 5 and 6) - and by subsequent ether cleavage. 1 is not identical with the alkaloid described under this structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198719870885
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Radikalreaktionen an N-Heterocyclen, VI. Reaktionen cyclischer 2,2-Diacyl-1-arylhydrazyle Eine neue N—N-Spaltungsreaktion (1987)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1987 (1987), S. 671-678 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Free Radical Reactions of N-Heterocyclic Compounds, VI. - Radical Reactions of Cyclic 2,2-Diacyl-1-arylhydrazyls. - A New N—N Bond Cleavage ReactionDiacylhydrazyl radicals 5 are generated from N-(phenylamino)-dicarboximides 1, 2a, b, 3a-f, and 4 by oxidation with different oxidants. The intermediates 5 react in two ways depending on the substituents in the anilino group. Dimerization of the hydrazyl radicals 5 to stable tetrazanes 8 is favoured by acceptor substituents in the Ar group. N—N bond dissoziation (α-decomposition) of the hydrazyl radicals 5 is favoured by donor substituents in the phenyl ring of the anilino group. The fragments of such reactions are imide radicals 22 and phenylnitrenes 23. The formation of these fragmentation products is proven by analysis of the reaction products. The formation of benzoxazole (25) (15% yield) is an evidence for an intramolecular insertion reaction of the o-methoxyphenylnitrene, generated by oxidation of 3e. The hydrazyl radicals 5 are also trapped by the stable free radical 2,4,6-tri-tert-butylphenoxyl (9). The thermal decomposition of the isolated radical adducts was studied.
    Notes: Die Diacylhydrazyl-Radikale 5 werden aus den N-(Phenylamino)dicarbonsäureimiden 1, 2a, b, 3a-f und 4 durch Oxidation mit verschiedenen Oxidantien erzeugt. Die Radikale 5 reagieren auf zwei Wegen: a) Dimerisation zu Tetrazanen 8, die durch Akzeptorsubstituenten im Anilinorest begünstigt wird; b) durch N—N-Bindungsspaltung, wobei Imid-Radikale 22 und Phenylnitrene 23 entstehen, bei donatorsubstituierten Anilinogruppen. Die Spaltprodukte werden als Folgeprodukte nachgewiesen, so Benzoxazol (25) (15%), das durch Oxidation von 3e über das intermediäre o-Methoxyphenylnitren gebildet wird. Die Hydrazyl-Radikale 5 konnten durch 2,4,6-Tri-tert-butylphenoxyl (9) abgefangen werden. Die Zersetzung der isolierten Abfangprodukte wurde untersucht.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198719870806
    Location Call Number Expected 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...