| 1 | Author
| T. Deforth, M. Kaschke, H. Stock, H. Pritzkow, W. Siebert | Requires cookie* | | Title
| Synthesis of C2B3 X-Heterocycles (X = C, N, P, O, S) from l,3?5-Triborapentanes  | | | Abstract
| The hydroboration of acetylene with HBCb yields the products (CbB^CHM e (la), (Cl2BCHMe)2BCl (2a), (Cl2BCHMeBCl)2CHMe (3a), and (ClBCHMe)3 (4a). The crystal structure of 4a as well as of the pentaiodo derivative 2b were determined. A mechanism for the formation of the different hydroboration products is proposed. The 1,3,5-triborapentane 2a serves as precursor for the synthesis of derivatives of 1,3,5-triboracyclohexanes, 1,3,5-tribora-2-aza-cyclohexanes, l,3,5-tribora-2-phospha-cyclo-hexanes, and 1,3,5-tribora-2-thia-cyclohexanes. Their constitutions have been derived from spectroscopic studies. The crystal structure of the 1,3,5-tribora-2-oxa-cyclohexane derivative was also determined. | | |
Reference
| Z. Naturforsch. 52b, 823—830 (1997); received March 4 1997 | | |
Published
| 1997 | | |
Keywords
| Hydroboration, 1, 3, 5-Triborapentanes, 1, 3, 5-Triboracyclohexanes, l, 3, 5-Tribora-2-oxa-cyclo-hexanes, 1, 3, 5-Tribora-2-aza-cyclohexanes | | |
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| default:Reihe_B/52/ZNB-1997-52b-0823.pdf | | | Identifier
| ZNB-1997-52b-0823 | | | Volume
| 52 | |
2 | Author
| Thomas Dezember, Helmut Sitzmann | Requires cookie* | | Title
| Die Fulven-Route zum Pentaisopropylcyclopentadienid The Fulvene Route to Pentaisopropylcyclopentadienide  | | |
Reference
| Z. Naturforsch. 52b, 911—918 (1997); eingegangen am 21. April 1997 | | |
Published
| 1997 | | |
Keywords
| 1, 2, 3, 4-Tetraisopropyl-6-dimethylamino-pentafulvene, 1, 2, 3, 4-Tetraisopropyl-6-methyl-pen-tafulvene, 1, 2, 3, 4-Tetraisopropylpentafulvene, Lithium Pentaisopropylcyclopentadienide, Ful vene Complexes | | |
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| | | | TEI-XML for
| default:Reihe_B/52/ZNB-1997-52b-0911.pdf | | | Identifier
| ZNB-1997-52b-0911 | | | Volume
| 52 | |
3 | Author
| Tristram Chivers, Masood Parvez, Peter Zoricak | Requires cookie* | | Title
| Preparation and X-Ray Structure of 4-BrC6H4CNSC(Cl)N  | | | Abstract
| The title compound was obtained in 82% yield by the intramolecular cyclization of 4-BrC6H4C(NSCCl3)[N(SiMe3)2] in CH2CI2 at 23°C. It crystallizes in the triclinic system, space group PI, a = 7.957(3) Ä, b = 10.864(5) A, c = 5.625(1) A, a = 95.94(3)°, ß = 97.79(2)°, 7 = 100.72(3)°, V = 469.2(3) A3, and Z -2. The bond lengths of the planar C2N2S ring indicate partial 7r-delocalization. | | |
Reference
| Z. Naturforsch. 52b, 557—559 (1997); received September 5 1996 | | |
Published
| 1997 | | |
Keywords
| Crystal Structure, 1, 2, 4-Thiadiazole, Intramolecular Cyclization | | |
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| default:Reihe_B/52/ZNB-1997-52b-0557.pdf | | | Identifier
| ZNB-1997-52b-0557 | | | Volume
| 52 | |
4 | Author
| Z. Ah Id, M. Aq, L+-, M. Ashooda, H. Asan, KevinT. Pott, M. Alik++, C., T. Anveer, A., N. Izam Ic, W. Olfgang | Requires cookie* | | Title
| Syntheses of Anomeric Pairs of New C-Nucleosides via 1,3-Dipolar Cycloaddition Reaction, Part I  | | | Abstract
| A convenient pathway to a variety of ß-and a-C-nucleosides has been developed by utiliz ing 1,3-dipolar cycloaddition reactions of various exocyclic and endocyclic heterocyclic ylides with ß (5a) and a (5b) anomers of ethyl 3-(2',3'-0-isopropylidene-5'-0-trityl-D-ribofurano-syl) propiolate, respectively. Assignment of configuration at exposition of the C-nucleosides could be made by a comparative study of the properties of corresponding a and ß anomers with a reasonable degree of certainity. | | |
Reference
| Z. Naturforsch. 52b, 1383—1392 (1997); received July 21 1997 | | |
Published
| 1997 | | |
Keywords
| C-Nucleosides, 1, 3-Dipolar Cycloadditions | | |
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| default:Reihe_B/52/ZNB-1997-52b-1383.pdf | | | Identifier
| ZNB-1997-52b-1383 | | | Volume
| 52 | |
5 | Author
| Clemens Krempner1, Rhett Kempeb, Hartmut Oehme3 | Requires cookie* | | Title
| The Thermal Isomerization of a Tetrahydro-2,3-disilanaphthalene into a 1,2-Disilacyclobutane -The Conversion of a Formal Silene [2+4] Cyclodimer into the [2+2] Cycloadduct  | | | Abstract
| 1,2,3,8a-Tetrahydro-1 -mesityl-5,7,8a-trimethyl-2,2,3,3-tetrakis(trimethylsilyl)-2,3-disila-naphthalene (3), the formal [2+4] cyclodimer of the transient 2-mesityl-l,l-bis(trimethylsilyl)-silene (2), on thermal treatment gradually isomerizes to give a mixture of the [2+2] products (E)-and -predominantly -(Z)-3,4-dimesityl-1,1,2,2-tetrakis(trimethylsilyl)-l,2-disilacyclo-butane [(E/Z)-4], By prolonged heating or at higher temperatures both (E/Z)-3 and (Z)-4 are converted into (E)-4, the thermodynamically most stable head-to-head dimer of 2. Possible pathways of the isomerization processes are discussed. | | |
Reference
| Z. Naturforsch. 52b, 815—818 (1997); received February 14 1997 | | |
Published
| 1997 | | |
Keywords
| Silenes, Silene Dimerization, 2, 3-Disilanaphthalene Tetrahydro, 1, 2-Disilacyclobutane | | |
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| default:Reihe_B/52/ZNB-1997-52b-0815.pdf | | | Identifier
| ZNB-1997-52b-0815 | | | Volume
| 52 | |
6 | Author
| Z. Naturforsch | Requires cookie* | | Title
| Acyclo C-Nucleosides Analogues of Condensed 1,2,4-Triazines  | | | Abstract
| 1-Acyclo C-nucleosides of 7-methyl-10//-l,2,4-triazolo[3,,4':3,4][l,2,4]triazino[5,6-£>]indoles (9) have been prepared by cyclodehydrogenation of the sugar derivatives of 3-hydrazino-8-methyl-5//-l,2,4-triazino[5,6-6]indole (1). The respective linear isomer as 4 has been pre pared by a dehydrative cyclization of the amides of 1. Acetylation of the sugar hydrazones and their cyclized products gave the per-7V,0-acetyl derivatives. The molecular connectivity of the products was established by *H, 13C, and 2D H ,H Cosy spectra. | | |
Reference
| Z. Naturforsch. 52b, 873—882 (1997); received February 17 1997 | | |
Published
| 1997 | | |
Keywords
| Acyclo C-Nucleoside, 1, 2, 4-Triazine, Indole, Triazinoindole, Triazolotriazinoindole | | |
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| default:Reihe_B/52/ZNB-1997-52b-0873.pdf | | | Identifier
| ZNB-1997-52b-0873 | | | Volume
| 52 | |
7 | Author
| Hans-Peter Schrödel, Alfred Schmidpeter | Requires cookie* | | Title
| Phosphorandiyl-l,3,5-triphosphinane/ Phosphonio-l,3,5-triphosphinin Kationen Phosphoranediyl-l,3,5-triphosphinanes / Phosphonio-l,3,5-triphosphinine Cations  | | | Abstract
| Depending on the reaction conditions, the condensation of triphenylphosphonium bis(trimethylsilyl)methylide 1 with phosphorus trichloride and phosphorus tribromide gives the cyclic trimers (Ph3P=CP-X)3, X = Cl, Br, trihalo-tris(triphenylphosphoranediyl)-1,3,5-triphosphinanes 3 and 5. In solution the compounds dissociate to give the ionic forms 4 and 6 which rapidly exchange the halide between the halophosphine and the phosphenium moieties. The exchange is slowed down when the halide ion is replaced by a tosylate ion. Substitution of the covalent chloride of 4 for diphenylphosphino groups gives again an ionic product 10, while the introduction of a morpholino group as well as the replacement of all chloride by triflate give dicationic compounds 12 and 13. Reaction of 3 with gallium trichloride finally leads to the tris(triphenylphosphonio)-l,3,5-triphosphinine trication as a major equilibrium participant. | | |
Reference
| Z. Naturforsch. 52b, 162—168 (1997); eingegangen am 24. Oktober 1996 | | |
Published
| 1997 | | |
Keywords
| Phosphonium Ylides, Halophosphines, Phosphenium Ions, 1, 3, 5-Triphosphinines, Halide Exchange | | |
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| default:Reihe_B/52/ZNB-1997-52b-0162.pdf | | | Identifier
| ZNB-1997-52b-0162 | | | Volume
| 52 | |
8 | Author
| Lothar Beyer | Requires cookie* | | Title
| Substituierte l,2,4-Thiadiazolium-dichloroaurate(I) und -tetra- chloroaurate(III) als Reaktionsprodukte von N-Thiocarbamoyl- benzamidinen mit TetrachIorogold(III)-Verbindungen  | | | Abstract
| Substituted 1,2,4-T hiadiazolium dichloroaurates(I) and -tetrachloroaurates(III) as Products o f the R eaction o f N -T hiocarbam oyl-benzam idines w ith Tetrachlorogold(III) Com pounds U w e Schröder3, R ainer R ichter3, Jürgen H artung3, U lrich A bram b, | | |
Reference
| Z. Naturforsch. 52b, 620—628 (1997); eingegangen am 12. März 1997 | | |
Published
| 1997 | | |
Keywords
| 1, 2, 4-Thiadiazoliumchloroaurates(I/III), Synthesis, X-Ray, EM Spectra, N-Thiocarbamoylbenzamidines | | |
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| default:Reihe_B/52/ZNB-1997-52b-0620.pdf | | | Identifier
| ZNB-1997-52b-0620 | | | Volume
| 52 | |
10 | Author
| J. W. Wheeler3, L. Nyalley3, D. M. Davisb, P. J. Weldonc | Requires cookie* | | Title
| Additional Sulfur Compounds from the Anal Glands of the Striped Polecat, Ictonyx striatus (Mustelidae, Mammalia)  | | | Abstract
| Two sulfur compounds have been identified in the anal gland secretions of captive-raised adults of the striped polecat (Ictonyx striatus), an African mustelid. 3-Ethyl-l,2-pentanedithiolane was observed in the secre tions of an adult male and an adult female. 1,3-Pen tanedithiol was observed in the male; this compound has not previously been reported from mustelid anal glands. | | |
Reference
| Z. Naturforsch. 52c, 283—285 (1997); received December 16 1996/February 4 1997 | | |
Published
| 1997 | | |
Keywords
| Ictonyx striatus, Striped Polecat, Anal Gland Secretions, 3-Ethyl-l, 2-pentanedithiolane, 1, 3-Pentanedithiol | | |
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| default:Reihe_C/52/ZNC-1997-52c-0283_n.pdf | | | Identifier
| ZNC-1997-52c-0283_n | | | Volume
| 52 | |
11 | Author
| G. Unther Seitz, Johanna Siegl | Requires cookie* | | Title
| Synthese neuer Pyridin-C-nukleoside der 2 ,3 -D i d e s o x y r i b o s e durch "inverse" [4+2]-Cycloaddition Synthesis of Novel Pyridine-C-nucleosides of 2,3-Dideoxyribose by "Inverse" [4+2]-Cycloaddition  | | | Abstract
| The anomeric imido esters 5 and 6, appropriate precursors for C-nucleoside synthesis, were prepared and utilized as heterodienophiles in a Diels-Alder reaction with inverse electron | | |
Reference
| Z. Naturforsch. 52b, 851—858 (1997); eingegangen am 22. April 1997 | | |
Published
| 1997 | | |
Keywords
| Pyridine-C-nucleosides, "Inverse" [4+2] Cycloadditions, 1, 2, 4-Triazine-C-nucleosides, 2, 3'-Dideoxy-/?-D-ribofuranosyl-pyridines | | |
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| default:Reihe_B/52/ZNB-1997-52b-0851.pdf | | | Identifier
| ZNB-1997-52b-0851 | | | Volume
| 52 | |
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