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1Author    Uwe KlingebielRequires cookie*
 Title    Reaktionen von Lithio-aminofluorsilanen mit Halogensilanen und Trimethylzinnchlorid Reactions of Lithio-aminofluorosilanes with Halogensilanes and Trimethyltinchloride  
 Abstract    Fluorosilanes react with lithium amides and organolithium compounds to give amino-fluorosilanes. (Lithioamino)fluorosilanes are formed by the reaction of aminofluoro-silanes with butyllithium depending on the steric influence and molecular stabilization of the ligands. These lithium salts react with halogensilanes and trimethyltin chloride with substitution. By LiF elimination the lithio-aminofluorosilane C6H5-SiF-NLiC(CH3)3-N(p-C6H4CH3Si(CH3)3) cyclisizes through a (2-j-2)cycloaddition and SiC-H-cleavage. 
  Reference    Z. Naturforsch. 33b, 521—526 (1978); eingegangen am 3. Januar/21. Februar 1978 
  Published    1978 
  Keywords    Lithio-aminofluorosilanes, Substitution, Cyclisation, NMR 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0521.pdf 
 Identifier    ZNB-1978-33b-0521 
 Volume    33 
2Author    W. N. Speckamp, J. Dijkink, P. Pasman, J. C. HubertRequires cookie*
 Title    Indole [3,2 gjindolizidines via Sodium Borohydride Reduction of Indolic Imides  
 Abstract    Acid-controlled sodium borohydride reduc-tion of imides followed by cyclisation of the carbinol lactams formed affords the title compounds in good yields. 
  Reference    (Z. Naturforsch. 33b, 127—128 [1978]; received September 12 1977) 
  Published    1978 
  Keywords    Reduction, Imides, Cyclisation, Carbinol Lactam, Indole Alkaloids 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0127_n.pdf 
 Identifier    ZNB-1978-33b-0127_n 
 Volume    33 
3Author    William Clegg, Uwe Klingebiel, Cornelia Krampe, GeorgeM. SheldrickRequires cookie*
 Title    .3-Silylgruppenwanderung im Si2NSiN-Gerüst - Synthese und Molekülstruktur von 1.3-Diaza-2.4-disilacyclobutanen 1,3-Migration of Silylgroups in the Si2NSiN-System - Synthesis and Molecular Structure of l,3-Diaza-2,4-disilacyclobutanes  
 Abstract    N-Organylamino-N',N'-bis(trimethyl)amino-fluoroorganylsilanes react with butyl-lithium to give the corresponding lithium salts. Further reaction of these lithium salts with fluorosilanes leads to the formation of the expected substituted compounds. Diaza-disilacyclobutanes are formed by thermal LiF elimination in THF. The simultaneous 1,3-migration of a trimethylsilyl group from one nitrogen atom to another is demonstrated by the crystal structure determination of the products of two such reactions, with different substituent groups. 
  Reference    Z. Naturforsch. 35b, 275—281 (1980); eingegangen am 26. Oktober/18. Dezember 1979 
  Published    1980 
  Keywords    Lithio-aminofluorosilanes, Silylgroup Migration, Cyclisation, Crystal Structure 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0275.pdf 
 Identifier    ZNB-1980-35b-0275 
 Volume    35 
4Author    Edgar Niecke, Anke Nickloweit-Lüke, Reinhold Rüger, Bernt Krebs, Helmut GreweRequires cookie*
 Title    .2A 3 .3A 3 -Azadiphosphiridine -Synthese, Kristallstruktur und Eigenschaften 1,2 A 3 ,3 x 3 -Azadiphosphiridines -Synthesis, Crystal Structure and Proj)erties  
 Abstract    1,2 A 3 ,3 A 3 -Azadiphosphiridines are avaüable by elimination of hydrogenhalide from ß-and y-functional molecular frameworks and by 1 + 2 cycloaddition of phosphinidenes towards aminoiminophosphanes. In contrast to other three-membered phosphorus com-pounds, azadiphosphiridines decompose by 2 +1 cycloreversion to aminoiminophosphanes and phosphinidenes. The molecular structure of an azadiphosphiridine demonstrates the trans arrangement of the exocyclic ligands and the planarity of the endocyclic nitrogen. 
  Reference    Z. Naturforsch. 36b, 1566—1574 (1981); eingegangen am 13. Juli 1981 
  Published    1981 
  Keywords    Azadiphosphiridines, Cyclisation, Thermal Decomposition, NMR Spectra, Crystal Structure 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1566.pdf 
 Identifier    ZNB-1981-36b-1566 
 Volume    36 
5Author    William Clegg, Uwe Klingebiel, GeorgeM. SheldrickRequires cookie*
 Title    Cyclisierungsreaktionen lithiierter Fluorsilanole und Aminofluorsiloxane - Kreuzdimerisierung eines Silicenium-Ylids Cyclisation Reactions of Lithiated Fluorosilanols and Aminofluorosiloxanes - Cross-dimerisation of a Silicenium-Ylid  
 Abstract    KOH reacts with bis(isopropyl-trimethylsilyl)-amino-difluorosilane to give the fluoro-silanol 1. An aminofluorosiloxane 2 is obtained in the reaction of [(Me3Si)2N]2SiF2 with KOH via a 1,3-silyl-group migration. The four-membered SiOSiN ring 5 can be prepared in several steps from 1. Six-membered SiO rings 8-10 are formed in the reaction of 1,3-fluorosilanols 6 and 7 with butyllithium. Lithiated 2 reacts with PCI3 to give a four-membered P2N2 ring 11, and with 2-methyl-2-propenal to give two isomeric (2 + 4) cycloadducts 12 and 13. The silicenium ylid formed initially by thermal elimation of LiF from lithiated 2 in PE/THF cross-dimerises to give a Si2N2 ring 14. If the reaction is carried out in n-heptane, the product after recrystallisation from acetone, 16, is an isomer of 14. The crystal structures of 14 and 16 have been determined. 
  Reference    Z. Naturforsch. 37b, 423—431 (1982); eingegangen am 14. Dezember 1981 
  Published    1982 
  Keywords    Fluorosüanols, Aminofluorosiloxanes, Cyclisation, Cross-dimerisation, Crystal Structure 
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 TEI-XML for    default:Reihe_B/37/ZNB-1982-37b-0423.pdf 
 Identifier    ZNB-1982-37b-0423 
 Volume    37 
6Author    Uwe Klingebiel, Norbert Vater, William Clegg, Martin Haase, GeorgeM. SheldrickRequires cookie*
 Title    Synthesis of Silicon-Phosphorus-Rings - Structure of a cis-2,2,4,4-Tetrakis(silylamino)-l,3-diphospha-2,4-disilacyclobutane  
 Abstract    Fluorosilylphosphanes of the type R2SiFPHR' (R = CHMe2, CMe3, NMeSiMe3; R' = H, C6H5; 1-4) are obtained in the reaction of difluorosilanes with lithiated phosphanes in a molar ratio 1:1. Diphosphasilanes (5, 6) and a difluorosilylphosphane (7) are isolated as by-products. 1-4 react with w-QjHgLi to give cyclic silylphosphanes, LiF, and C4H10 (8-11). Dilithiated 5 reacts with F2PN(CMe3)SiMe3 to form of a four-membered SiP3-ring 12. The 31 P NMR spectra of 9 and 11 show signal coalescence for the eis-and tfrans-isomers at room temperature. The crystal structure of the cis-isomer of 11 has been determined. The substituted ring 13 is prepared in the reaction of lithiated 9 and Me2SiF2. 
  Reference    Z. Naturforsch. 38b, 1557—1562 (1983); eingegangen am 6. Juli 1983 
  Published    1983 
  Keywords    Fluorosilylphosphanes, Cyclisation, P-Inversion, Isomers, Crystal Structure 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1557.pdf 
 Identifier    ZNB-1983-38b-1557 
 Volume    38 
7Author    D. Ietm Ar Stalke, Nayla Keweloh, Uwe Klingebiel, M. Atthias, N. Oltem Eyer, G. Eorge, M. SheldrickRequires cookie*
 Title    Von lithiierten Aminofluorsilanen zu mono-und dimeren Iminosilanen From Lithiated Aminofluorosilanes to Mono-and Dimeric Iminosilanes  
 Abstract    Depending on the solvent and the bulkiness of the substituents, lithiated aminofluorosilanes are dimers, monomers, or LiF-adducts of iminosilanes. In the crystal structure of the dimeric lithium derivative of di-terr-butyl(/m-butylamino)fluorosilane, each lithium atom is coordinated by one fluorine and two nitrogen atoms. LiF-elimination leads — if sterically possible — to dimerisation. The limits of dimerisation are reached with the dimer diisopropyl(trwm-butylphenyl-imino)silane, for which the crystal structure analysis shows severe steric distortions. Fluorine-chlorine-exchange occurs in reactions of lithiated (tri-fm-butylphenylimino)fluorosilanes with Me3SiCl. Iminosilanes are obtained by thermal LiCl-elimination from the resulting salts. 
  Reference    Z. Naturforsch. 42b, 1237—1244 (1987); eingegangen am 4. Mai/25. Juni 1987 
  Published    1987 
  Keywords    Aminofluorosilanes, Lithium Salts, Cyclisation, Iminosilanes, Crystal Structure 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-1237.pdf 
 Identifier    ZNB-1987-42b-1237 
 Volume    42 
8Author    AndrzejE. WróRequires cookie*
 Title    A nalogues o f Methyl Y)-Ribo-and D-Arafo/io-furanosides Having Phosphorus in the Anomeric Position+  
 Abstract    Acid-catalysed cyclisation of (1SJ-and (1R)-1-C-(dimethoxyphosphinyl)-D-erythritols gave exclu­ sively P-epimeric analogues of methyl D -ribo-and D-arabino-furanosides with phosphorus in the anom eric position. 
  Reference    Z. Naturforsch. 41b, 791 (1986); received Decem ber 12 1985 
  Published    1986 
  Keywords    Polihydroxy-l, 2-oxaphospholanes, Cyclisation, Regioselectivity, Configuration, ljC N M R Spectra 
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 TEI-XML for    default:Reihe_B/41/ZNB-1986-41b-0791_n.pdf 
 Identifier    ZNB-1986-41b-0791_n 
 Volume    41 
9Author    R. Balamurali, K.J Rajendra PrasadRequires cookie*
 Title    A Facile Synthesis of Quino[2,3-fl]carbazoles  
 Abstract    Condensation of l-oxo-l,2,3,4-tetrahydrocarba-zoles la-e and o-aminoacetophenone 2 under acid catalysis afforded a new class of quino[2,3-a]car-bazoles 3a-e in good yields. A plausible mecha­ nism for the product formation is also proposed. 
  Reference    Z. Naturforsch. 54b, 1618—1620 (1999); received June 14 1999 
  Published    1999 
  Keywords    l-Oxo-l, 2, 34-tetrahydrocarbazole, o-Amino-acetophenone Condensation, Cyclisation, Aerial Oxidation 
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 TEI-XML for    default:Reihe_B/54/ZNB-1999-54b-1618_n.pdf 
 Identifier    ZNB-1999-54b-1618_n 
 Volume    54