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  • 1
    Electronic Resource
    Electronic Resource
    The Pagodane Route to Dodecahedranes Scope and Limitation of the Dehydrocyclization StratagemDedicated to Prof. Dr. George A. Olah on the occasion of his 65th birthday. (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 1741-1751 
    Details
    ISSN: 0009-2940
    Keywords: Bissecododecahedranes, hydrogenolysis, catalytic dehydrocyclization ; Dodecahedranes ; Cyclizations, non-dehydrogenative ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The stepwise route B from pagodanes to dodecahedranes was completed by double catalytic dehydrocyclization of saturated (alkylated) bisseco precursor substrates (2, 3, 5, 16). Based on pagodane, dodecahedranes (9, 10, 13, 14, 17) were obtained in up to 53% yield. Transannular C,C bond formation at the bisseco stage and partial (C-alkyl) or total (C-OR, C-CO2R) removal of substituent groups under the necessarily forcing reaction conditions constituted preparative limitations. Attempts at alternative ring closure methodologies (homo-Norrish type II, homoenolization, carbene insertion) have remained unsuccessful.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921250729
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  • 2
    Electronic Resource
    Electronic Resource
    From an Insecticide to Plato's Universe - The Pagodane Route to Dodecahedranes: New Pathways and New PerspectivesDedicated to Professor Christoph Rüchardt on the occasion of his 65th birthday (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 33 (1994), S. 2239-2257 
    Details
    ISSN: 0570-0833
    Keywords: Cage compounds ; Polycycles ; Hydrocarbons ; Dodecahedranes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The original concept for the synthesis of pentagonal dodecahedranes by the conversion of structurally similar, high-energy [1.1.1.1]pagodanes relied on catalytic dehydrocyclizations. As a consequence, preparative limitations were preprogrammed. With multiple functionalization of these pagodanes, alternative cyclization methods became viable. These efficient processes allowed access to a multitude of pentagonal and nonpentagonal, carba- and heterocyclic dodecahedral skeletons with widely variable substitution patterns. Such a roundabout route provided the (CH)20 basic framework with high efficiency, and long-lacking thermochemical data could be ascertained calorimetrically. In spite of the unusually pronounced pyramidalization of their olefinic centers, singly and doubly unsaturated dodecahedranes with isolated C=C bonds proved to be kinetically quite stable, but underwent dimerization on thermal activation. Dodecahedranes with a higher degree of unsaturation (trienes-decaenes, C20 fullerene?) have been found so far only in the gas phase. Higher fullerenes, including C60, have been identified by mass spectrometry after exposure of halogenated dodecahedranes and pagodanes to a 248-nm excimer laser. Transannular electron delocalization has been verified for the “slender” pagodane/isopagodane and even for the “spherical” dodecahedrane cages.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/anie.199422391
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    Paper (German National Licenses)
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