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'benzene' in keywords Facet   section ZfN Section B  [X]
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1983 (1)
1981 (1)
1972 (1)
1Author    H.-D LüdemannRequires cookie*
 Title    The Interaction between Pyrimidine Nucleosides and Benzene in Aqueous Solution, studied by Proton Magnetic Resonance  
  Reference    (Z. Naturforsch. 27b, 1196—1201 [1972]; received May 2/June 15 1972) 
  Published    1972 
  Keywords    Interaction, nucleosides, benzene, water, PMR 
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 TEI-XML for    default:Reihe_B/27/ZNB-1972-27b-1196.pdf 
 Identifier    ZNB-1972-27b-1196 
 Volume    27 
2Author    FrancisL. Tanzella, Neil BartlettRequires cookie*
 Title    Quantitative Synthesis of (C6H5)2AsF2+AsF6-and (C6H5)2A8F3 via Interaction of Benzene with Arsenic Pentafluoride  
 Abstract    Benzene reacts quantitatively with AsFs to give (C6H5)2AsF2 + AsF6-, the first reported aryl or alkyl fluoroarsonium(V) salt. This reacts quantitatively with CsF to give (CeH5)2AsF3 and CsAsF6. Interaction of (C6H5)2AsF3 with AsF5 reconstitutes the fluoro-arsonium salt. Variable temperature 19 F NMR studies show (CÖHS^ASFS to be a rigid trigonal bipyramid, with the phenyl groups in equatorial positions. 
  Reference    Z. Naturforsch. 36b, 1461—1464 (1981); received May 18 1981 
  Published    1981 
  Keywords    Arylfluoroarsonium, Arsenic, Benzene, Substitution 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1461.pdf 
 Identifier    ZNB-1981-36b-1461 
 Volume    36 
3Author    D. Bryce-Smith, A. Gilbert, N. Al-Jalal, R. R. Deshpande, J. Grzonka, M. A. Hems, P. YianniRequires cookie*
 Title    Acid and Polarity Effects in Benzene Photoreactions with Alkenes and Alkynes  
 Abstract    The effects of polar solvents and proton donors on various photoreactions of the benzene ring with electron-acceptor alkenes and alkynes are described and discussed in relation to the various electronic excitation mechanisms involved. Proton donors prove valuable as mechanistic probes for polar intermediates in such processes, and can in some systems both initiate and divert reaction pathways. In 1970 we observed that the course of the photo-chemical cycloadditions of certain ethylenic and acetylenic compounds to benzene, earlier reported by us [1, 2], was profoundly altered in the presence of proton donors, leading to a type of photochemical Friedel-Crafts reaction [3]. Since then, we have described, mostly in preliminary form, numerous further examples of acid catalysis in the photo-reactions of benzene, viz. with amines [4], ethers [5], a ketone [6], a carboxylic acid [6], and hexa-fluorobenzene [7]. Our objective in this present paper is to bring together the previous preliminary reports on acid catalysis in the photoreactions of ethylenic and acetylenic compounds with benzene in conjunction with unpublished recent findings, and to provide a mechanistic rationale together with relevant experimental details. But before we proceed to consider the acid-cata-lysed processes, it is desirable to summarise the main types of reaction that have been shown to occur in the absence of acids. Ethylenes and/or acetylenes photoadd to benzene in the following four main ways: (a) ortho cycloaddition; (b) meto-cycloaddi-tion; (c) £>ara-cycloaddition; and (d) para-ene addi-tion [8, 9]. The mode of addition varies with the addend, and in some cases more than one pathway may be followed. In the case of (a), the adducts (1) of ethylenes may be obtained as such when the ethylenic addend is not a strong thermal dienophile, e.g. acrylonitrile [10], 2,3-dihydropyran [11]. When it is a strong dienophile, as in the case of maleic * Reprint requests to Prof. D. Bryce-Smith. 0340-5087/83/0900-1101/$ 01.00/0 anhydride and certain maleimides, a second mole-cule may add thermally to give the remarkably 
  Reference    Z. Naturforsch. 38b, 1101—1112 (1983); received May 2 1983 
  Published    1983 
  Keywords    Photoreactions, Benzene, Alkenes, Alkynes, Acid Effects 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1101.pdf 
 Identifier    ZNB-1983-38b-1101 
 Volume    38