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
  • 1
    Electronic Resource
    Electronic Resource
    Crown-containing styryl dyes (1993)
    Springer
    Russian chemical bulletin 42 (1993), S. 1385-1389 
    Details
    ISSN: 1573-9171
    Keywords: crown-containing styryl dyes ; complexes with Mg2+ ; photocyclodimerization ; cyclobutane derivatives ; 1H and13C NMR spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Styryl dyes containing a crown ether group and a heteroaromatic moiety with a sulfoalkylN-substituent (1a,b) undergo photocyclodimerization in acetonitrile in the presence of Mg(ClO4)2 to give only the typeA isomer of cyclobutane derivative (2a,b). The photochemical regio- and stereoselectivity of the cycloaddition is explained by self-organization of thetrans-isomers of the styryl dyes upon complexation with the Mg2+ cations into dimers with a fixed mutual arrangement of multiple bonds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699938
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Crown ether styryl dyes (1996)
    Springer
    Russian chemical bulletin 45 (1996), S. 654-661 
    Details
    ISSN: 1573-9171
    Keywords: crown ether styryl dyes ; synthesis ; complexation ; anion-“capped” complexes ; [2+2] photocycloaddition ; cyclobutane derivatives ; 1H NMR spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract New crown ether styryl dyes (trans-1c,d) containing the 18-crown-6 ether fragment were synthesized. Interaction oftrans-1c,d dyes, as well as their analogs,trans-1a,b containing the 15-crown-5 ether fragment, with Ca(ClO4)2 in MeCN afforded supramolecular structures (dimeric complexes). Competing reactions,trans-cis-photoisomerization with the formation of anion-“capped” complexes ofcis-1a—d and [2+2] autophotocycloaddition with the formation of cyclobutane derivatives8a—d and9c, were observed on photolysis of solutions of complexes oftrans-1a—d with Ca2+. Preorganization oftrans-isomers in dimeric complexes with Ca2+ determined the regio- and stereoselectivity of each of the two directions of the photocycloaddition and the efficiency of the reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01435800
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Synthesis of formyl derivatives of benzocrown ethers containing N, S, and O heteroatoms in the macrocycle (1995)
    Springer
    Russian chemical bulletin 44 (1995), S. 116-123 
    Details
    ISSN: 1573-9171
    Keywords: 4′-bromobenzocrowns, synthesis, metallation ; 4′-formylbenzocrown ethers ; semicarbazones and oximes of 4′-formylbenzocrown ethers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A method for the synthesis of 4′-bromobenzodithia-15(18)-crown-5(6) and 4′-bromobenzodiaza-15 (18)-crown-5(6) by condensation of 3,4-di(2′-haloethoxy)bromobenzene with polyoxaalkanes containing terminal SH or NHMe groups was suggested. The method for the synthesis of formyl derivatives of benzocrowns containing N, S, and O heteroatoms in the macrocycle based on the metallation of appropriate bromo derivatives with BunLi followed by treatment of the resulting organolithium intermediates with DMF was developed. Oximes and semicarbazones of benzaldehydes containing a crown ether fragment were obtained, and their transformation into the original aldehydes by treatment with KNO2 in an acid medium was studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696971
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Crown-ether styryl dyes (1995)
    Springer
    Russian chemical bulletin 44 (1995), S. 2131-2136 
    Details
    ISSN: 1573-9171
    Keywords: crown ether styryl dyes ; complex-formation ; [2+2]-photocycloaddition ; cyclobutane derivatives ; 1H NMR spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Styryl dyes (4a,b) containing a 15-crown-5 fragment and isomeric 2- and 4-quinolinium residues with anN-sulfopropyl substituent undergo [2+2]-autophotocycloaddition to give cyclobutane derivatives (9a,b) in acetonitrile only in the presence of Mg(ClO4)2 or Ca(ClO4)2. The stereospecificity of both pathways of photocycloaddition and its efficiency are explained by the preorganization of the supramolecular dimers derived from thetrans-isomers of the dyes when they are bound into complexes with Mg and Ca cations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696719
    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...