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
Filter
  • Cell & Developmental Biology  (2,745)
  • Chemical Engineering  (1,368)
  • Inorganic Chemistry  (1,294)
  • Computational Chemistry and Molecular Modeling  (991)
  • 1995-1999  (3,147)
  • 1990-1994  (3,251)
  • 1980-1984
  • 1975-1979
  • 1995  (3,147)
  • 1993  (3,251)
  • 1929
Collection
Keywords
Publisher
Years
  • 1995-1999  (3,147)
  • 1990-1994  (3,251)
  • 1980-1984
  • 1975-1979
  • 1925-1929  (887)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Synthese, Struktur und Umlagerung von Chlorbis(2,4,6-tri-tert-butylphenyl)gallan (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2255-2257 
    Details
    ISSN: 0009-2940
    Keywords: Gallane, chlorobis(supermesityl) ; Rearrangement ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis, Structure, and Rearrangement of Chlorobis(2,4,6-tri-tert-butylphenyl)gallaneThe title compound 1 is easily obtained from GaCl3 and 2 equvialents of supermesityllithium. According to an X-ray structure analysis one of the supermesityl rings shows a large deviation from planarity. Heating of 1 in vacuo gives mainly two products: an isomer of 1 in which one of the supermesityl groups is bound to Ga by one of its tert-butyl groups (2) and a benzo[b]gallolane (3) formed by elimination of HCl, X-ray structure analyses and full NMR (1H, 13C) data are provided for 1 and 2, MS and characteristic NMR (1H, 13C) data for 3.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261014
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Masthead (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, LXXX. Insertions- und Additions-Reaktionen an Diphosphamanganacyclopropanen mit aktivierten Alkinen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 23-29 
    Details
    ISSN: 0009-2940
    Keywords: Diphosphamanganacyclopropanes ; Alkyne insertion ; Alkyne addition ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metal-;Containing Heterocycles: Preparation, Properties, Reactions, LXXX.  -  Insertion and Addition Reactions on Diphosphamanganacyclopropanes with Activated AlkynesThe thermally and kinetically stable diphosphamanganabicyclooctadienones 3a  -  e [R2 = tBu: R1 = iPr (a), nPr (b), Ph (c); R2 = Cy: R1 = nPr (d), Ph (e)] are obtained by the reaction of the alkyne (CCO2Me)2 with the diphosphamanganacyclopropanes (OC)4Mn-PR12=PR2 (2a  -  e). Depending on steric factors the formation of 3a  -  e occurs in two different ways. In a first step the alkyne is inserted into the P  -  P bond of 2a  -  e to give the kinetically labile five-membered rings 1a  -  e. Subsequently another alkyne is added to the PR2 and a CO group of 1a  -  e to give 3a  -  e. In an alternative way the alkyne is added first to the PR2 and a CO group of 2a with formation of the diphosphamanganabicyclohexenone 4a. Insertion of a second alkyne into the P  -  P bond of 4a affords the bicyclooctadienone 3a. Compound 2a, 3c, and 4a have been characterized by X-ray structural analyses.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen, CXIV. Organorhenium(VII)-oxide (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 45-50 
    Details
    ISSN: 0009-2940
    Keywords: Rhenium compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Multiple Bonds between Main Group Elements and Transition Metals, CXIV.  -  Organorhenium(VII) OxidesAlkylrhenium(VII) oxides of formulae RReO3 and RReO3 · L (L = quinuclidine) result from dirhenium heptaoxide and dialkylzinc compounds at low temperatures in THF solution. Unbranched, noncyclic organorhenium oxides prove to be less thermolabile than branched-chain derivatives, with the thermal stability decreasing with increasing chain length. Complexes with branched carbon chains normally can be isolated as 1:1 adducts of a nitrogen base, e.g. quinuclidine. A first chiral alkylmetal oxide and base-stabilized cyclopropyltrioxorhenium(VII) are also described.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Notizen / Notes [Li2(THF)4DAD] und [DAD  -  H][ZrCl5(THF)]: Neue Strukturvarianten phenylsubstituierter 1,4-Diaza-1,3-dien-Liganden (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 57-61 
    Details
    ISSN: 0009-2940
    Keywords: Lithium compounds ; Enediamide structure ; 1,4-Diaza-1,3-diene, protonated ; Hydrogen bond ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [Li2(THF)4DAD] and [DAD  -  H][ZrCl5(THF)]: New Types of Phenyl-;Substituted 1,4-Diaza-1,3-diene LigandsTwo extreme situations in 1,4-diaza-1,3-diene (DAD) chemistry are described. Reaction of phenyl-substituted DAD 1a  -  c with lithium in the molecular ratio of 1:2 affords in high yield the extremely air-sensitive complexes [Li2(THF)4DAD] (2a  -  c). The structure of 2b has been determined by X-ray diffraction. Each of the Li+ ions is coordinated by the two terminal N atoms of the s-cis-configurated DAD dianion and by two molecules of THF. Protonation of ZrCl4 · DAD (3a) by HCl in THF gives the ionic complex [ZrCl5(THF)][DAD  -  H] (4), which contains a protonated [DAD  -  H]+ cation. The structure of the sterically crowded N = C  -  C = N skeleton of the [DAD  -  H]+ cation is not influenced by the positive charge and adopts the unusual Z-gauche-Z conformation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Reaktive E = C(p-p)π-Systeme, XXXIII. Side-on-Koordination des Phosphaalkins P ≡ C  -  N(iPr)2 im 16e-Nickel(0)-Komplex Ni(CO)PCy3[PCN(iPr)2] (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 63-65 
    Details
    ISSN: 0009-2940
    Keywords: Phosphaalkyne, amino- ; Nickel carbonyl phosphane complex ; π Coordination ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactive E = C(p-p)π Systems, XXXIII.  -  Side-on Coordination of the Phosphaalkyne P ≡ C  -  N(iPr)2 in the 16e Nickel(0) Complex Ni(CO)PCy3[PCN(iPr)2]The reaction of (diisopropylamino)phosphaethyne P ≡ C  -  N(iPr)2 with the nickel complex [Ni(CO)3PCy3] - in contrast to the analogous reactions with Ni(CO)4 or Ni(CO)3PR3 (R = Me, Ph) - leads to the novel 16e nickel(0) system [Ni{η2-P ≡ C  -  N(iPr2)}(CO)PCy3] with a planar geometry of all skeleton atoms besides the methyl and cyclohexyl groups. Side-on coordination of the P ≡ C triple bond results in an increase of the PC distance to 1.665 Ȧ typical for phosphaalkenes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Zur Tautomerie von 5,5-Diphenyldihydro-4H-1,2,3-triazol-4-on und 5-Amino-4,4-diphenyl-4H-1,2,3-triazolen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 103-108 
    Details
    ISSN: 0009-2940
    Keywords: 1,2,3-Triazol-4-ones, 3,5-dihydro-4H- ; 1,2,3-Triazoles, 5-amino-4H- ; Tautomerism ; 15N-NMR Spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tautomerism of 5,5-Diphenyldihydro-4H-1,2,3-triazol-4-one and 5-Amino-4,4-diphenyl-4H-1,2,3-triazolesMethylation of the 5-amino-4H-1,2,3-triazole 5 affords the N-methyl- (12) and the N,N-dimethylaminotriazole 13. X-ray diffraction analyses show that the tautomer 5b exists in the crystal and that 5b and 13 possess similar structures and atomic distances. Both compounds exhibit restricted rotation of the amino groups in solution. The comparison of UV, carbon-13 and nitrogen-15 spectra of the tautomeric triazoles 2 and 5 with those of the N-methyl compounds 3 and 13 demonstrates that the tautomers 2a and 5b are strongly favoured also in solution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    3a,6-Dihydro-3H-imidazo[1,2-d]tetrazole aus 1- und 4-Phenacyl-1H-tetrazolium-Salzen und Ammoniak (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 129-132 
    Details
    ISSN: 0009-2940
    Keywords: 3H-Imidazo[1,2-d]tetrazoles, 3a,6-dihydro- ; Tetrazolium salts, 1,5-dialkyl(aryl)-4-phenacyl- ; reaction with ammonia ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3a,6-Dihydro-3H-imidazo[1,2-d]tetrazoles from 1- and 4-Phenacyl-1H-tetrazolium Salts and AmmoniaTreatment of the tetrazolium salts 1 with aqueous ammonia affords the novel ring system 2 (in certain cases along with the ylides 3). The structure of 2 has been confirmed by an X-ray analysis of 2a.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Crystal Structure of the Explosive Parent Benzyne Precursor: 2-Diazoniobenzenecarboxylate Hydrate (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 243-249 
    Details
    ISSN: 0009-2940
    Keywords: Benzyne precursor ; Neighboring group interactions ; Incipient nucleophilic attack ; 2-Diazoniobenzenecarboxylate ; Calculations, ab initio, MO ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structure of the highly unstable benzyne precursor 2-diazoniobenzenecarboxylate (3) has been determined by single-crystal X-ray diffraction. The structure is discussed in comparison to ab initio results for several conformers of 3, related aromatic diazonium ions, and phenyl cation and also to crystal structures of simple diazonium ion salts and of benzoates. Structural features and characteristic distortions are related to the electron density distributions and to intra- and intermolecular interactions between the neighboring functional groups.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Darstellung und Charakterisierung von Anthrylenmagnesium-Innerkomplexen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 225-237 
    Details
    ISSN: 0009-2940
    Keywords: Anthracene derivatives ; Magnesium anthracene inner complexes ; 13C CP/MAS NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation and Characterization of Inner Complexes of AnthrylenemagnesiumAnthracene derivatives containing ether or amino groups in 9- or 9,10-position (1 - 10) react with magnesium to form new magnesium anthracene inner complexes (11 - 20). These complexes as well as their organic starting materials have been extensively characterized by spectroscopy and chemical means. It was found that solvent ligands which are present in all magnesium anthracene complexes known to date can be partially or totally replaced by inner complexation. For some of the new magnesium anthracene inner complexes the complex formation rates have been determined.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260131
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Reversibility of the [2 + 2] Cycloaddition of Isocyanates to Glycals (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 265-267 
    Details
    ISSN: 0009-2940
    Keywords: [2 + 2] Cycloaddition, reversible ; Glycals ; Isocyanates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [2 + 2] Cycloadducts obtained by the addition of tosyl isocyanate to glycals (10 - 13) undergo retro-addition upon heating or even at room temperature. The rate of retro-addition increases with rising temperature and polarity of the solvent.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Synthesis and Aggregation Properties in Solution of a New Octasubstituted Copper Phthalocyanine: {2,3,9,10,16,17,23,24-Octakis-[(dioctylaminocarbonyl)methoxy]phthalocyaninato}copper(II) (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 269-271 
    Details
    ISSN: 0009-2940
    Keywords: Phthalocyanine, soluble ; Cation-induced phthalocyanine aggregates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the octasubstituted phthalocyanine 1, highly soluble in organic solvents, is described. Its aggregation properties in different solvents and in the presence of alkaline, alkaline earth, and ammonium salts are studied.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260137
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Organometall-Oxide  -  Höhervalente Derivate der d-Metall-Säuren, 6. Tris(3,5-dimethyl-1-pyrazolyl)boranato-substituierte Alkyl(dioxo)1-, Methylenphosphoranyl(dioxo)1- und s̰1-Allyl(dioxo)1-Komplexe des Molybdäns und Wolframs (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 289-296 
    Details
    ISSN: 0009-2940
    Keywords: Oxo complexes, organometallic ; Borato, hydrotris(3,5-dimethyl-1-pyrazolyl)1-, complexes ; Molybdenum complexes ; Tungsten complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organometallic Oxo Complexes  -  Highervalent Derivatives of the d-Metal Acids, 6.  -  Hydrotris(3,5-dimethyl-1-pyrazolyl)borato-Substituted Alkyl(dioxo)1-, Methylenephosphoranyl(dioxo)1-, and s̰1-Allyl(dioxo) Complexes of Molybdenum and TungstenTp*MoO2Cl (1) and Tp*WO2Cl (2) [Tp* = κ31-HB(3,5-Me2pz)3] react with trimethyl aluminium to form the corresponding dioxo(methyl) complexes Tp*MO2(CH3), M=Mo (3), W (4). An X-ray crystal structure analysis of 3 is performed. The less oxidizing tungsten complex 2 is alkylated by Grignard reagents to yield alkyl complexes of the type Tp*WO2R 5-7 [R=CH2SiMe3, CH2tBu and CH2C(Me)Ph2] and the s̰1-2-methallyl complex Tp*WO2(CH2CMe=CH2) 8. Reactions of 2 with methylenephorphoranes R3P=CH2 (R=iPr, Ph) give transylidation products Tp*WO2(CHPiPr3) (9) and Tp*WO2(CH-PPh3) (10). Hydrolysis of 10 leads to a trioxotungstate [Tp*WO3]- (11), stabilized by a hydroxyphosphonium cation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    all-Homocalixarene: Carbocyclische Wirtverbindungen mit intra- und extraannularen Ligandarmen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2483-2491 
    Details
    ISSN: 0009-2940
    Keywords: Carbocycles ; Homocalixarenes ; Calixarenes, Homo- ; Large rings ; Macrocycles ; [2n]Metacyclophanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: all-Homocalixarenes: Carbocyclic Host Compounds with Intra- and Extraannular Ligand ArmsMethoxy-substituted [2n]metacyclophanes 1-10, obtained by Müller-Röscheisen cyclization, are converted into all-homocalixarenes 11-20 with free phenolic hydroxy functions. The well-soluble cyclic pentamer 11 and octamer 14 with endo-acidic host properties are investigated with regard to guest binding. They exhibit selectivity towards alkaline earth metal ions (Ba2+) in liquid/liquid extraction studies. Some of the macrocyclic oligophenols are transformed into homocalixarenes 21-25 with intra- or extraannular oxapropionate groups. The diester 22 and the tetraester 23 are converted into carbocycles 26 and 27 with two and four free oxapropionic acid groups. Complexation properties of the oligoesters in extraction studies and log K values in water are reported. X-ray structural analyses were performed of the [6]-, [8]- and [4]- homocalixarenes 9 and 21, 14 and 23; the inclusion of solvent molecules is proven.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Preparation and Conformational Studies of Ethylene-Bridged Calixarene-Analogous Macrocyclic Metacyclophanes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2501-2504 
    Details
    ISSN: 0009-2940
    Keywords: [(2.1)n]Metacyclophanes, hydroxy- ; Calixarenes ; Trans-tert-butylation ; Conformation ; Hydrogen bonding, intramolecular ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The novel macrocyclic compounds hexahydroxy[2.1.2.1.2.1]- (7b) and octahydroxy[2.1.2.1.2.1.2.1]metacyclophane (7c) have been prepared from anisole in six steps by using the tert-butyl function as a positional protective group on the aromatic ring. Base-catalyzed condensation of 1,2-bis(5-tert-butyl-2-hydroxy-phenyl)ethane (5) with formaldehyde in refluxing xylene does not afford the dimeric product, tetrahydroxy[2.1.2.1]metacyclophane 6a, but furnishes the larger macrocycles 6b and 6c in 70-90% yield. AlCl3/MeNO2-catalyzed trans-tert-butylation of 6b and 6c in toluene gives the desired metacyclophanes 7b and 7c in 60 and 80% yields, respectively, along with tert-butyltoluene 8b. The conformations of the systems such as trimer 6b and tetramers 6c, 7c have been evaluated from their dynamic 1H-NMR spectra. The tetramer 6c is fixed to form a “pleated-loop” conformation like the calix[8]arenes due to the much more stronger intramolecular hydrogen bonding among the hydroxyl groups than in the trimer 6b.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Stereoselectivity of the Thermally Initiated Free-Radical Chain Addition of Cyclohexane to 1-Alkynes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2493-2499 
    Details
    ISSN: 0009-2940
    Keywords: Radicals ; Addition ; Stereoselectivity ; Alkynes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alkanes can be added to alkynes in a thermally initiated free-radical chain reaction (“ane reaction”). The addition of cyclohexane to 1-alkynes 1a-1 yields a mixture of (Z)- and (E)-2-cyclohexyl-1-alkenes 3a-1. An essential step in this reaction is the addition of cyclohexyl radicals to the alkynes to give 2-cyclohexyl-1-alkenyl radicals 2a-1 which abstract hydrogen from cyclohexane to yield the products 3a-1. The stereoselectivity of the addition has been measured in the temperature range of 160-260°C. It strongly depends on the substituent X of the radical center and varies over a range of almost four orders of magnitude from [(Z)-3a]:[(E)-3a] = 33 (X = OMe) at 160°C to [(Z)-31]:[(E)-31] = 0.012 (X = tBu) at 260°C. The stereoselectivity is further influenced by the temperature and in most cases by the concentration of the hydrogen donor cyclohexane. The reaction is discussed in terms of the stereoselectivity of the addition of cyclohexyl radicals to the alkyne, of the structure of the 1-alkenyl radical (σ and π radical, respectively), the rate of inversion in the case of σ alkenyl radicals, and the relative rates of syn and anti hydrogen transfer.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261124
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Medium-Sized Cyclophanes, 29. Synthesis and Desulfurization of 2,11-Dithia[3]metacyclo- and 2,11-Dithia[3]paracyclo[3](4,9)pyrenophanes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2505-2511 
    Details
    ISSN: 0009-2940
    Keywords: Cyclophanes ; Benzenopyrenophane, 4,9-bridged ; Sulfones, pyrolysis of ; Photodesulfurization ; [2]Naphthaleno[2]paracyclophane, 1,5-bridged ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2,11-Dithia[3]metacyclo- (14b) and 2,11-dithia[3]paracyclo[3]-(4,9)pyrenophane (14c) were obtained by the coupling reactions of 4,9-bis(chloromethyl)pyrene (12) with the corresponding bis(mercaptomethyl)benzenes (13b, c). Attempted pyrolysis of the disulfones 18b, 18c to afford [2]metacyclo- (19b) and [2]paracyclo[2](4,9)pyrenophane (19c) failed. Only the ring cleavage products 16 and 20 were obtained. The sulfur dioxide extrusion by vapor-phase pyrolysis of the corresponding disulfone 18 to the highly strained 19 clearly demonstrates the limits of these preparative ring contraction method. The photolytic desulfurization of 14c afforded the [2](1,5)naphthal-eno[2]paracyclophane analogue 21 instead of [2]paracyclo[1]-(4,9)pyrenophane 21′. The mechanism of the pyrolysis and photolysis reactions is discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261126
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Flow-Vacuum Pyrolysis of Polycyclic Compounds, 6. Pyrolysis of Dibenzo [CH]8 Hydrocarbons (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2513-2517 
    Details
    ISSN: 0009-2940
    Keywords: Dibenzo [CH]8 hydrocarbons ; Flow-vacuum pyrolysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The flow-vacuum pyrolysis of dibenzo [CH]8 hydrocarbons 2,3,4, and 5 are studied at 1 Torr and in the temperature range between 400 and 650°C. The following new transformations have been observed: 2⇆4, 2→5, 3→5, 3⇆4, 3→2, 5→11, the last three presenting analogies in the [CH]8 and/or benzo [CH]8 series. A reaction mechanism is suggested.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    On the Reaction of 1-Aza-2-azoniaallene Salts with Carbodiimides (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2519-2524 
    Details
    ISSN: 0009-2940
    Keywords: 1-Aza-2-azoniaallene cations ; Carbodiimides ; 1H-1,2,4-Triazolium salts ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-Aza-2-azoniaallene cations 3, prepared in situ from geminal (chloroalkyl)azo compounds 2, react with carbodiimides 4 to give 4,5-dihydro-5-imino-1H-1,2,4-triazolium salts 7. An X-ray structural analysis was carried out for 71. According to AM1 calculations the cycloaddition of carbodiimides to 1-aza-2-azoniaallene cations occurs in a nonconcerted manner via cyanamidium cations 5 as intermediates. Hetero-Wagner-Meerwein rearrangements of the primary cycloadducts 6 provide the final products 7.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Organophosphorverbindungen, 73. Der Tri-tert-butyl-2-cyclopropen-1-yl-Rest als kinetisch stabilisierende Gruppe für 1-Aza-3-phosphaallene (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2525-2530 
    Details
    ISSN: 0009-2940
    Keywords: Phosphanes, cyclopropenyl- ; Phosphaalkenes, cyclopropenyl ; Shifts, [1,3]-silyl and [1,3]-H ; 1-Aza-3-phosphaallenes ; Cyclopropenyl substituents ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organophosphorus Compounds, 73[1]. - The Tri-tert-butyl-2-cyclopropen-1-yl Substituent as Kinetically Stabilizing Group for 1-Aza-3-phosphaallenes[2]The cyclopropenylphosphane 5 reacts with the isocyanates 6a-g to form the phosphaalkenes 7a-g. An analogous transformation occurs with the same phosphane and the bifunctional isocyanates 8a, b (→ 9a, b). In contrast, the reaction 5 + 6h ends at the stage of the tautomers 11h ⇆ 12h. Methanolysis of 7b and of 11h ⇆ 12h leads to the carbamoyl-cyclopropenylphosphanes 14a and b, respectively. Sodium hydroxide-catalyzed elimination of hexamethyldisiloxane from 7b, g and the tautomer mixture 11h ⇆ 12h yields the target 1-aza-3-phosphaallenes 16a-c.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261129
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    4,5,12,13-Tetrabromo[2.2]paracyclophane - A New Bis(aryne) Equivalent (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2531-2534 
    Details
    ISSN: 0009-2940
    Keywords: [2.2]Paracyclophanes ; 1,2-Dibromoarenes ; anti-[2.2]Paracyclophanes ; Aryne generation ; Diels-Alder reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of 2 with nBuLi at -78°C generates aryne intermediates within the aromatic rings of [2.2]paracyclophane which are trapped in Diels-Alder reactions with dienes like furan, 1,9-diphenylisobenzofuran, or cyclopentadiene. Reductive deoxygenation with low-valent titanium reagents or TMSI converts the adducts of furan and isobenzofuran into anti-[2.2]paracyclophanes 4 and 5, respectively. The reaction of two aryne intermediates with [2.2](2,5)furanophane (7) yields 8 with three [2.2]paracyclophane units arranged in a stair-like fashion; yet, in this compound the highly shielded oxygen atoms cannot be removed anymore by reduction.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Coordinated 1-Aza-1,3-butadienes: Stable Intermediates in the Formation of Pyridines from [(β-Aminoethenyl)carbene]chromium Complexes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2535-2541 
    Details
    ISSN: 0009-2940
    Keywords: Chromium, (β-aminoethenyl)carbene complexes ; 1-Aza-1,3-butadienes, coordinated ; Pyridines, cycloaddition with alkynes ; Chelated chromium complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [(β-Aminoethenyl)carbene]chromium complexes 3a-c rearrange to coordinated 1-aza-1,3-butadienes 6a-c, which undergo cycloadditions with alkynes 7a, c to pyridines 9a, 10a-c.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261131
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    A Soluble Benzodifluoranthene Derivative by Dehydration of an Oxygen-Bridged Precursor (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2543-2546 
    Details
    ISSN: 0009-2940
    Keywords: Multicyclic aromatic hydrocarbons, dehydration to ; Multicyclic aromatic hydrocarbons, solubility of ; Benzodifluoranthene derivative ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and characterization of the alkyl chain-substituted benzodifluoranthene 6 are described. The final synthetic step involves an acid-promoted dehydration whose conversion is determined to be quantitative. The solubilities of compounds 4e, 5, and 6 are qualitatively correlated with structural features. The molecular structure of 6 in the crystal is elucidated by an X-ray structure analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261132
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Synthese mittlerer und großer Ringe, XXXIV. Stereoselektive Synthese überbrückter und verzweigter Methyl-desoxyfuranoside aus 3,6-Hexanooxepin-4,5-dicarbonsäure-dimethylester (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2547-2551 
    Details
    ISSN: 0009-2940
    Keywords: Furanosides, methyl ; Photochemistry ; Stereoselective reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of Medium and Large Rings, XXXIV[1,2]. - Stereoselective Synthesis of Bridged and Branched Methyl Deoxyfuranosides from Dimethyl 3,6-Hexanooxepine-4,5-dicarboxylateThe stereoselective synthesis of the bridged methyl furanosides 4-8 with four, five, and six stereogenic centers is described. The reaction sequence starts with the addition of methanol to the oxepine 1. The photochemical electrocyclic ring closure of 2 gives the cyclobutene 3. Ruthenium tetraoxide oxidation of 3 leads to the title compound 4 that is further converted to 5-8 by stereoselective reductions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Synthese, Struktur und Reaktivität von Diphosphiranen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 645-648 
    Details
    ISSN: 0009-2940
    Keywords: Diphosphiranes, molecular structure of ; 1,2-Diphospha-2-propene ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis, Structure, and Reactivity of DiphosphiranesThe 1,1-diamino-1,2-diphospha-2-propen (2,6-Me2C5H8N)2P - P=C(SiMe3)2 (3) is obtained by treatment of bis(2,6-dimethyl-piperidino)(trimethylsilyl)phosphane (1) with [bis(trimethylsilyl)methylene]chlorophosphane (2). Compound 3 readily undergoes thermally isomerization to the diphosphirane 2,6- Nucleophilic substitution of the P1-chloro function of 1-chloro-2-(diisopropylamino)1-3,3-bis(trimethylsilyl)diphosphirane (6) leads to alkyl, amino, phosphanyl, and arsanyl derivatives 7a - d. The corresponding hydrogen derivative 7e is formed by reduction of 6 with tri-n1-butylstannane. The molecular structure of 7c as well as the NMR data of the diphosphiranes are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Übergangsmetall-Stannyl-Komplexe, 7. Darstellung von Carben-Komplexen (π1-Aromat)(CO)2CrCR2 durch Umsetzung der anionischen Stannyl-Komplexe [(π1-Aromat)(CO)2CrSnPh3]- mit R2CX2 oder [R2CX]Y (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 657-664 
    Details
    ISSN: 0009-2940
    Keywords: Carbene complexes ; Stannyl complexes ; Chromium complexes ; Anionic complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Transition Metal Stannyl Complexes, 7[1]. - Preparation of Carbene Complexes (π1-Arene)(CO)2CrCR2 by the Reaction of the Anionic Stannyl Complexes [(π1-Arene)(CO)2CrSnPh3]- with R2CX2 or [R2CX]YCarbene complexes (π1-arene)(CO)2Cr=CR2 are formed in substitution/elimination reactions from the anionic stannyl complexes K[(π1-arene)(CO)2CrSnPh3] [π1-arene=C6H6 (1a), 1,3,5-Me3C6H3 (1b), 1,2,4,5-Me4C6H2 (1c)] C6Me6 (1d) and organic dihalides R2CX2 containing activated C - X bonds or ionic halides [R2CX]Y. Bis(stannyl) complexes (π1-arene)(CO)2Cr(SnPh3)2 (3) and hydrido(stannyl)complexes (π1-arene)(CO)2Cr(H)SnPh3 are formed as byproducts due to the reaction of the eliminated Ph3SnCl with the anionic starting complexes or electron transfer reactions, respectively. The portion and ratio of the byproducts is largely influenced by the steric properties of both the (π1-arene)(CO)2Cr fragment and the organic halide. Pyridinylidene complexes 2) are only obtained from 2-chloro-N1-methylpyridinium tetrafluoroborat with 1a - c, but not with 1d. With the sterically less demanding halides [R2N=C(H)Cl]Cl [NR2=NMe2, (n=3, 4)] or 3,3-dichloro-1,2-diphenylcyclopropene the carbene complexes (π1-arene)(CO)2Cr=C(H)NR2 or are obtained with all employed π1-arene ligands.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Vinyliden-Übergangsmetallkomplexe, XXII. Alkin-, Alkinyl(hydrido)1-, Vinyliden-und Vinylvinyliden-Komplexe des Rhodiums aus OH-, NH2- und Cl-funktionalisierten Alkinen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 669-678 
    Details
    ISSN: 0009-2940
    Keywords: Vinylidenerhodium complexes, γ1-functionalized, generation from alkynols and their derivatives ; (Vinylvinylidene)1- and allenylidenerhodium complexes, formation by HX elimination ; Alkynyl(hydrido)1- rhodium(III) complexes, preparation from alkyne or vinylidene precursors ; Rhodium complexes, cyclopentadienyl, with vinylvinylidene ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinylidene Transition Metal Complexes, XXII[1]. - Alkyne, Alkynyl(hydrido)1-, Vinylidene-, and Vinylvinylidene Complexes of Rhodium from OH-, NH2-, and Cl-Functionalized Alkynes
    Notes: The reaction of [RhCl(PiPr3)2]n with γ1-functionalized 1-alkynes HC≡C-CRR′X (X=OH, OMe, Cl, NH2) at room temperature leads to the formation of either alkyne-, alkynyl(hydrido)1-, or vinylidenerhodium complexes. The alkyne and alkynyl-(hydrido) derivatives rearrange thermally or in the presence of deactivated Al2O3 to the isomeric vinylidenerhodium compounds in almost quantitative yield. On treatment of the γ1-functionalized vinylidenerhodium complexes trans-[RhCl(=C=CH-CRR′X)(PiPr3)2] with Al2O3 or traces of acids, elimination of HX occurs and (for R=H, CH3; R′=CH3; X=OH, Cl, NH2) the (vinylvinylidene)rhodium compounds trans-[RhCl(=C=CH-CR=CH2)(PiPr3)2] are formed. In contrast, the reaction of trans-[RhCl(=C=CHCPh2OH)(PiPr3)2] with either Al2O3 or acid gives the allenylidene complex trans-[RhCl(=C=C=CPh2)(PiPr3)2]. The 1-hexyne derivatives HC≡C[CH2]3CH2X (X=OH, Cl) react with [RhCl(PiPr3)2]n to give alkyne-, alkynyl(hydrido)1-, and vinylidenerhodium compounds; attempts to form the cyclic vinylidene complex trans- by HX elimination from trans-[RhCl(=C=C=CH[CH2]3CH2X)(PiPr3)2] (X=OH, Cl) failed. The half-sandwich-type (vinylvinylidene)rhodium compounds [C5H5Rh(=C=CH-CR=CH2)(PiPr3)] (R=H, Me) are obtained from [RhH(C≡C-CR=CH2)Cl(py)(PiPr3)2] and NaC5H5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260318
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    (Bicyclo[3.2.0]hepta-1,3-dienyl)cobalt(I) Complexes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 713-724 
    Details
    ISSN: 0009-2940
    Keywords: Bicyclo[3.2.0]hepta-1,3-dienyl complexes ; Calculations, semiempirical ; Alkyne trimerization ; Cobalt complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three isomeric bicyclo[3.2.0]heptadienes 1 - 3 are compared by semiempirical calculations. Experimental attempts directed to the synthesis of derivatives of 1 are described. The synthesis, properties and some reactions of (η51-bicyclo[3.2.0]hepta-1,3-dienyl)(η41-cycloocta-1,5-diene)cobalt(I) (22), including an X-ray crystal structure determination of the reaction product with diphenylethyne, the tetraphenylcyclobutadiene complex 30, are presented.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260323
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Synthese und Struktur von Phosphiren-Iminen und Iminophosphaspiro[2.2]pentanen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 649-655 
    Details
    ISSN: 0009-2940
    Keywords: λ51-Phosphirenes, imino- ; λ51-Phosphaspiro[2.2]pentanes, imino ; Imines ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Structure of Phosphirene Imines and Iminophosphaspiro[2.2]pentanesThe reaction of the iminophosphanes R1P=NR2=[1, R2=2,4,6-tBu3C6H2;R1=Me (a) Et (b), PhCH=CH (c), Cl (d); R2=tBu, R1=Et3C (e)] with the alkynes R3C ≡ CR4 [2, R3=R4=Ph (a), CO2Me (b)] affords the corresponding phosphirene imines 3a - g. A [2 + 1] cycloadduct 3h is also formed in the reaction of the alkyne 2c (R3=H, R4=Ph) with 1d, while in the case of 1b the 1,2-addition product 4 is obtained. As demonstrated by the [2 + 1] cycloaddition reaction of the P1-alkylated iminophosphanes 1a, b with methylene-cyclopropanes 5a, b, the formation of the iminophosphaspiro[2.2]pentanes 6a, b is observed. The structures of the P/C heterocycles 3a, b and 6b have been determined by NMR spectroscopy and X-ray analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Schwefel(IV)1-Verbindungen als Liganden, 19. Kationische Ruthenium-Sulfen-Komplexe: Synthese und Reaktionen. Kristallstrukturanalyse von [Cp*(Me3P)2Ru(CH2=SO2)]PF6 (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 679-684 
    Details
    ISSN: 0009-2940
    Keywords: Ruthenium complexes ; Sulfur dioxide complexes ; Sulfene complexes ; Nucleophilic addition ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sulfur(IV) Compounds as Ligands, 19[1]. - Cationic Ruthenium-Sulfene Complexes: Synthesis and Reactions. Crystal Structure Analysis of [Cp*(Me3P)2Ru(CH2=SO2)]PF6Methylene addition to coordinated sulfur dioxide yields the novel η2(C, S) sulfene complexes [Cp(dppm)Ru(CHR=SO2)]PF6 (R=H:3, Me: 4) and [Cp*(Me3P)2Ru(CH2=SO2)]PF6 (5). An X-ray structure determination of 5 reveals a relatively short C - S bond (167.5 pm). The sulfene complexes are powerful carbon electrophiles as shown by the rapid addition of halides, pseudohalides, amines, including „nonnucleophiles“ such as ethyldiisopropylamine and DBU, and phosphanes to 3. The regioselectivity of the reaction of 3 with enamines is opposite to that of free sulfene, i.e. coordination of the sulfene to ruthenium effects umpolung.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260319
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Monofunktionelle tetraedrische Zink-Komplexe L3ZnX [L3=Tris(pyrazolyl)borat] (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 685-694 
    Details
    ISSN: 0009-2940
    Keywords: Zinc complexes ; Tris(pyrazolyl)borat ligands ; Reactivity ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monofunctional Tetrahedral Zinc Complexes L3ZnX [L3=Tris(pyrazolyl)borate]The pyrazolyl borates K[HBpz3*] (abbreviated KL3, pz*=3-phenyl-, 3-tolyl-, 3-anisyl-3,5-diphenyl pyrazolyl) react with zinc salts ZnX2 (X=Cl, Br, I, NO3) to form the mononuclear neutral tetrahedral zinc complexes L3ZnX (1 - 4). The corresponding alkylzinc complexes L3ZnR (5 - 8; R=Me, Et, tBu, Ph) result either from L3ZnCl and LiR or from ZnEt2 and KL3. These alkylzinc compounds are remarkably stable towards oxidation and hydrolysis. For specific cases the reaction of L3ZnR with carboxylic acids is found to yield the carboxylates L3ZnOCOR (9, 10), and likewise with thioacetic acid to yield the thioacetates L3ZnSCOMe (11). Facile cleavage of L3ZnR with thiols and selenophenol produces the thiolates L3ZnSR (12, 13) and the selenolates L3ZnSePh (14). The complexes L3ZntBu which are the most reactive of the alkylzinc compounds are cleaved by H2O, H2S, NH3 and various OH and NH compounds with formation of the bis(ligand) complexes Zn(L3)2 (15). Crystal structure determinations of one L3ZnX complex each for X=NO3 (4a), CH3 (5a), SCOMe (11a), and SEt (12a) confirm the nature of the compounds and the relation of 4a and 12a to the active centers of zinc-containing enzymes.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260320
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Nucleophile Singulett-Carbene in der [4 + 1]1-Cycloaddition mit 1,2,4,5-Tetrazinen: Eine neue Isopyrazol-Synthese (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 733-738 
    Details
    ISSN: 0009-2940
    Keywords: Singlet carbenes ; [4 + 1] Cycloadditions ; Isopyrazoles ; Diels-Alder reactions ; [4 + 2] Cycloreversion ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nucleophilic Singlet Carbenes in the [4 + 1] Cycloaddition with 1,2,4,5-Tetrazines: a New Synthesis of IsopyrazolesA series of 3,6-disubstituted 1,2,4,5-tetrazines 6, including C6H5, SCH3, SO2CH3, N(CH3)2, CF3, CO2CH3 groups, has been submitted to [4 + 1] cycloaddition with the nucleophilic singlet carbenes 4, 15, and 20, which are generated from the precursors 1, 11 and 19, resp. In all cases isopyrazoles (4H1-pyrazoles) 9, 10, 18, and 21 are isolated in good yields. They are formed in a two-step reaction sequence with the [4 + 1] cycloadducts of type 8 as intermediates which eliminate nitrogen by subsequent [4 + 2] cycloreversion. The acceptor-substituted isopyrazole 9e is characterized as an electron-deficient diene by some Diels-Alder reactions with inverse electron demand leading to the expected azo-bridged cycloadducts 23, 25, 27, 29, and 31 without acid catalysis or application of higher pressure. With cyclooctyne (32), the [4 + 2] cycloaddition is followed by a [4 + 2] cycloreversion with formation of the cyclopentacyclooctene 34.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260325
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Metall-π1-Komplexe von Benzolderivaten, XLI. Bis(η61-anilin)chrom: Synthese, Redoxverhalten und Brønsted-Basizität (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 399-404 
    Details
    ISSN: 0009-2940
    Keywords: Chromium complexes ; Aniline as an η61-ligand ; Voltammetry, cyclic ; Nerst-Clark plots ; Acid dissociation constants ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metal π Complexes of Benzene Derivatives, XLI[1].  -  Bis(η61-aniline)chromium: Synthesis, Redox Properties and Brønsted BasicityBis(η61-aniline)chromium (6) has been prepared by protodesilylation of its N,N,N′,N′1-tetrakis(trimethylsilyl) derivative 5, which is accessible by metal-atom ligand-vapor cocondensation (cc). Bis(η61-dimethylaniline)chromium (3) is obtained directly from cc. The couples 3+/0 and 6+/0 feature the most negative redox potentials E1/2 ever reported for bis(arene)1-metal complexes. According to EPR spectroscopy, applied to the radical cations 3+· and 6+· the site of oxidation is largely localized on the metal. The pH dependence of E1/2 is cast in Nerst-Clark plots, whose breaks supply the pKs values of the mono-and diprotonated forms of 3 and 6. η61-Coordination to CrI increases the basicity of aniline by three pK units, whereas η61-coordination to Cr1 effects a decrease by more than seven pK units. The first and second dissociation constants of the organometallic bis(ammonium) ions 3(H+)2 and 6(H+)2 differ by 2.7 pK units. This interval reflects the interaction of the two basic centers in 3 and 6 which approaches that of p1-phenylenediamine. Thus, conjugation across the bis(η61-arene)chromium unit is virtually uninhibited.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260216
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Bis(pentamethylcyclopentadienyl)keton und -thioketon: Kohlenstoff-Verbindungen mit präformierter Diels-Alder-Geometrie (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 415-420 
    Details
    ISSN: 0009-2940
    Keywords: 1,3-Cyclopentadiene-5-carbonyl chloride, 1,2,3,4,5-pentamethyl- ; 1,3-Cyclopentadiene-5-carbothioyl chloride, 1,2,3,4,5-pentamethyl- ; Ketone, bis(1,2,3,4,5-pentamethyl-1,3-cyclopentadien-5-yl) ; Thioketone, bis(1,2,3,4,5-pentamethyl-1,3-cyclopentadien-5-yl) ; Diels-Alder preformation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(pentamethylcyclopentadienyl) Ketone and Thioketone: Carbon Compounds with Performed Diels-Alder Geometry1,2,3,4,5-Pentamethyl-1,3-cyclopentadien-5-carbonyl chloride (2) is formed in good yields by the reaction of pentamethylcyclopentadienyllithium (1) with phosgene. The corresponding carbothioyl chloride 3 is synthesized by treatment of 1 with thiophosgene. Both acyl chlorides are stable against air and moisture and difficult to attack in SN2-type reactions. Treatment of 2 and 3 with trimethyl(pentamethylcyclopentadienyl)stannane in the presence of boron trifluoride  -  ether leads to bis(1,2,3,4,5-pentamethyl-1,3-cyclopentadien-5-yl) ketone (5) and thioketone (6), respectively. Even at room temperature, 5 and 6 tend to intramolecular [4 + 2] cycloaddition reactions. X-ray crystal structure investigations of 2, 5, and 6 show the steric demand of the pentamethylcyclopentadienyl ligand and explain the untypical chemical behavior of 2 and the easy [2 + 4] cycloaddition reactions of 5 and 6.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260219
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Multistep Redoxsystems, LX. 1,4,5,8-Tetraoxo-1,4,5,8-tetrahydrothianthrene: Synthesis, Structure, and Spectroelectrochemical Properties (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 465-471 
    Details
    ISSN: 0009-2940
    Keywords: Thianthrene derivatives ; X-ray analysis ; MO calculation ; Cyclovoltammetry ; UV-Vis spectroelectrochemistry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis, structure, cyclovoltammetric and spectroelectrochemical data of 1,4,5,8-tetraoxo-1,4,5,8-tetrahydrothianthrene (2a) are presented. A relation between the positive partial charge at the sulfur atom and the dihedral angle at the S—S axis is discussed on the basis of semiempirical MO calculations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260226
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Neue Beobachtungen zur Stereoselektivität von Monoiodcarben-Additionen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 499-502 
    Details
    ISSN: 0009-2940
    Keywords: Iodocarbene, addition to alkenes ; endo1-Selectivity ; Cyclooctadiene ; Cyclooctatetraene ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New Observations Concerning the Stereoselectivity of Monoiodocarbene AdditionsContrary to our earlier claim, CHI gives endo/exo isomer mixtures with cyclooctene. However, only endo1-iodo compounds 7, 8, 10-12 are obtained from COD and COT. Tricyclic compound 7 rearranges partially to bicyclic 9, X-ray structure determinations of 7 and 9 were performed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260229
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Reaktivität s̰1-bishomoaromatischer Heterocyclen: Elektrocyclische Reaktionen und Cycloadditionen von syn- und anti1-Bishomofuran und -BishomothiophenProfessor William von E. Doering zum 75. Geburtstag gewidmet. (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 485-498 
    Details
    ISSN: 0009-2940
    Keywords: Carbonyl ylides, generation from syn1-bishomofuran ; Thiocarbonyl ylides, generation from syn1-bishomothiophene ; Ylides, carbonyl and thiocarbonyl, 1,3-dipolar cycloaddition, electrocyclization, sigmatropic 1,4-hydrogen shift of ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactivity of s̰1-Bishomoaromatic Heterocyles: Electrocyclic Reactions and Cycloadditions of syn- and anti1-Bishomofuran and -BishomothiopheneProfessor William von E. Doering zum 75. Geburtstag gewidmet.The title compounds syn-4a, b and anti-4a, b, synthesized by the CuCl-catalyzed reaction of homofuran 1a or homothiophene 1b with diazomethane, are very different in their thermal stability. syn-4a isomerizes to 2,3-dihydrooxepine (7a) readily at 130°C whereas the rearrangement anti-4a → 7a requires a temperature of about 370°C. A similar difference in thermal reactivity is observed between syn-4b and anti-4b. But syn-4b undergoes in addition to the rearrangement to 2,3-dihydrothiepine (7b) a dimerization (to 12?) on thermolysis in [D6]benzene solution at 140°C, whereas mainly isomerization to 9b, cis-10b, and 11 (product of the elimination of sulfur from cis-10b) occurs on thermolysis in the gas phase. The formation of 7a and 7b, respectively, is explained by the electrocyclic ring opening of syn-4a or syn-4b leading to the carbonyl ylide 5a or the thiocarbonyl ylide 5b followed by a sigmatropic 1,4 hydrogen shift. To rationalize the additional products in the thermolysis of syn-4b an electrocyclic conrotatory ring closure in 5b leading to the highly strained episulfide trans-10b is assumed to complete with the hydrogen shift. Under the reaction conditions trans-10b is unstable and either dimerizes in solution or isomerizes in the gas phase. The formation of 9b in the thermolysis of syn-4b indicates that a two-step pathway may compete with the concerted process. syn-4a, b react with various π acceptor-substituted olefins to form cycloadducts of the general type 6a, b. The cycloaddition occurs stereospecifically cis with respect to the configuration of the starting olefin and non-stereoselectively with respect to the endo/exo ratio. The kinetic analysis of the reaction of syn-4a with fumaronitrile (FN), N1-phenylmaleinimide (NPMI) or dimethyl dicyanofumarate (DCFM) shows unambiguously, that the adducts are formed by a 1,3-dipolar cycloaddition of the intermediate carbonyl ylide 5a rather than a homo-Diels-Alder reaction of syn-4a (in contrast to the cycloaddition of homofuran 1a). A comparison between the enthalpies of reactions syn-4a → 5a (ΔHR ≤ 22.4 kcal/mol) and syn-4d → 5d (ΔHR ≥ 47.5 kcal/mol) shows the carbonyl ylide to be a 1,3-diradical, highly resonance-stabilized by the heteroatom (resonance energy R.E. ≍ -25 kcal/mol).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260228
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    1-Sila-3-alumina-4-aluminatacyclopentan mit Al-Al-Bindung und C2Al2Si-Heterocyclus (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2637-2641 
    Details
    ISSN: 0009-2940
    Keywords: Aluminium-aluminium bond ; C2Al2Si heterocycle ; Aluminium, three- and fourfold coordinated ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-Sila-3-alumina-4-aluminatacyclopentane with an Al-Al Bond and a C2Al2Si HeterocycleTetrakis[bis(trimethylsilyl)methyl]dialuminium(4) (1) with an aluminium-aluminium bond reacts in the presence of tetramethylethylenediamine (TMEDA) with the sterically highly shielded bases bis(trimethylsilyl)methyllithium or bis(dimethylphosphanyl)methyllithium to yield under deprotonation of a methyl group a carbanionic species, which is stabilized by an interaction with one of the coordinatively unsaturated Al atoms. The five-membered heterocycle 5 is formed containing two Al, one Si and two C atoms. The Al-Al bond remains uncleaved. Interestingly, 5 crystallizes in different crystals with and without crystal ether, which were both characterized by crystal-structure determinations. The Al-Al bond length in 5 [264.1(2) and 266.5(3) pm, respectively] is only slightly changed in comparison to the neutral starting compound 1 (266.0 pm). Under similar conditions the sterically less demanding ethyllithium leads to a β-elimination and addition of the thereby formed LiH to one of the two Al atoms to give the recently published hydridodialuminate(5) Li(TMEDA)2+ [R2Al-AlHR2]- (2).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Homo- und Hetero-Metall-Amide des Tris(tert-butylamino)methylsilans - Polycyclen und Cluster mit Li, Na, Mg, Al und Tl (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2625-2635 
    Details
    ISSN: 0009-2940
    Keywords: Amides, hetero metal ; Polycycles ; Metal clusters of thallium ; Metal nitrogen bonding ; Carbanion, stabilized by metal complexation ; Silane, tris(tert-butylamino) ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Homo and Hetero Metal Amides of Tris(tert-butylamino)methylsilane - Polycycles and Clusters with Li, Na, Mg, Al and TlThe hydrogen atoms attached to nitrogen in tris(tert-butyl-amino)methylsilane (1) can be substituted by metallic main-group elements in a quite general way. If 1 is treated with trimethylaluminium apart from the monosubstituted product MeSi(tBuNH)2(tBuNAlMe2) (2) the trisamide MeSi(tBuNAlMe2)3 (3) is obtained. In similar ways complete substitution of the amino hydrogen atoms in 1 yields the compounds MeSi[tBuNMgN(SiMe3)2]3 (6), [MeSi(tBuNLi)3]2 (10), and [MeSi(tBuNTl)3]2 (11), the later two being dimeric. If methyl-magnesium iodide is allowed to react with 1 the intermediate MeSi(tBuNMgI)3 (4) in some instances can be isolated as the THF adduct or may react with a further equivalent of the Grignard compound to generate the complex [MgI-(THF)5]+ [MeSi(tBuNMgI)3CH3 · THF]- (5). The aluminium compound 2 has been used to access to heterometallic amides combining aluminium and sodium as in MeSi(tBuNAlMe2)(tBuNNa)(tBuNH) (7) or magnesium and aluminium as in the dimeric compounds [MeSi(tBuNAlMe2)(tBuNH)(tBuNMgI)]2 (8) and [MeSi(tBuNAlMe2)(tBuNH)(tBuNMgMe)]2 (9). X-ray structure analyses reveal 3 (tricyclic SiN3Al3 skeleton with Al - N distances from 2.014 to 2.025 Å), 6 (tricyclic Si-N3Mg3 skeleton), and 7 [bicyclic SiN3AlNa skeleton with Na - N distances of 2.47(1) and 2.52(1) Å] to be monomeric even in the solid state. The compounds 8 and 9 (both pentacyclic with spiro magnesium atoms) form centrosymmetric dimers by Mg - I - Mg and Mg - (CH3) - Mg bridges, respectively. The dimers 10 and 11 are completely different in terms of chemical bonding: while in the lithium compound 10 a centrosymmetric polycycle is formed by principly ionic interactions of the lithium atoms with corresponding nitrogen atoms, the centrosymmetric dimer in 11 is held together by Tl - Tl bonds. The X-ray structure analysis of 5 reveals the anion containing a Mg-coordinated CH3-.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Tetraindeno-Fused Cyclooctatetraene and Oligomeric Biindenyls by Oxidative Coupling of 2,2′1-Biindenyl (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 969-973 
    Details
    ISSN: 0009-2940
    Keywords: 1,1′1-Bi(2,2′1-biindenylyls) ; Carbanions ; Oxidative coupling ; Cyclooctatetraindenes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lithiated biindenyls 2 and 4, prepared by deprotonation of 2,2′1-biindenyl (1) and 10,11-dihydrodiindeno[1,2-b:2′,1′-d]thiophene (3) with n1-butyllithium, are oxidatively coupled to give oligomeric biindenyls (17) as well as tetraindeno-fused eight-membered rings (16, 19, 24).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Zinkkomplexe von Aminosäuren und Peptiden, 2[1]. Koordination einfacher Histidin-Derivate an Zink (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2643-2648 
    Details
    ISSN: 0009-2940
    Keywords: Histidine derivatives ; Zinc complexes ; Solution equilibria ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Zinc Complexes of Amino Acids and Peptides, 2[1]. - Coordination of Simple Histidine Derivatives to ZincThe bis(L-histidine)ZnCl2 complex 1 is likely to have tetrahedral ZnN2Cl2 coordination. For the compound (L-histidine)-ZnCl2 · HCl (2) a structure determination has revealed a tetrahedral ZnOCl3 coordination. Of the C-protected histidine derivatives His-OMe and His-NH2 and zinc salts of non-coordinating anions the complexes (His-OMe)2ZnX2 (3) and (His-NH2)2Zn(ClO4)2 (4) were obtained. A structure determination of (His-OMe)2Zn(BPh4)2 · H2O has revealed a ZnN4 coordination with chelating histidine units. Of the N-protected histidine derivative Nα-acetylhistidine the complexes (Ac-His)ZnX · H2O (5, X = ClO4, BF4) have been isolated which are coordination polymers in the solid state. From pH-dependent 13C-NMR studies it is concluced that in solution the imidazole N and carboxyl O are coordinated to zinc in (Ac-His)Zn and (Ac-His)2Zn units. The doubly protected histidine derivative Bz-His-OMe acts as a monodentate ligand forming the tetrahedral complexes (Bz-His-OMe)4Zn(ClO4)2 (6) and [(Bz-His-OMe)2Zn(2,9-dimethyl-o-phenanthroline)](ClO4)2 (7).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Synthese und Röntgenstrukturanalyse einer neuartigen gemischtvalenten zwitterionischen Diphosphor-Fluor-Verbindung (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2653-2655 
    Details
    ISSN: 0009-2940
    Keywords: Diphosphorus zwitterion ; Phosphorus, hexacoordinated ; Phosphorus, tetracoordinated ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and X-Ray Crystal Structure Analysis of a Novel Mixed-Valent Zwitterionic Diphosphorus Fluoro CompoundThe cyclic zwitterionic λ6P,λ4P-diphosphorus compound F5P-N(Me)P+ [N(Me)C(=O)]2NMe (3), which contains a biuret system, was synthesized by the reaction of (MeNPF3)2 (1) with MeNCO (2). Compound 3 was characterized by means of 1H-, 13C-, 19F- and 31P-NMR spectroscopy, IR spectroscopy, and mass spectrometry. A single-crystal X-ray structure determination revealed the presence of two independent formula units, in which the -N(Me)PF5 side chains display widely differing conformations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Metallorganische Verbindungen der Lanthanoide, 82[1]. (2,5-Di-tert-butylpyrrolyl)-Komplexe von Neodym(III), Samarium(II) und Ytterbium(II): Synthese und Röntgenstrukturanalyse von dimerem Natrium-dichlorobis(2,5-di-tert-butylpyrrolyl)(tetrahydrofuran)neodymat(III) (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2657-2659 
    Details
    ISSN: 0009-2940
    Keywords: Azacyclopentadienyl complexes ; Neodymium compounds ; Samarium compounds ; Ytterbium compounds ; Lanthanoides, organo-, chlorides ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organometallic Compounds of the Lanthanoids, 82[1]. - [2,5-Di-tert-butylpyrrolyl) Complexes of Neodymium(III), Samarium(II), and Ytterbium(II): Synthesis and X-Ray Structural Analysis of Dimeric Sodium Dichlorobis(2,5-di-tert-butylpyrrolyl)(tetrahydrofuran)neodymiate(III)NdCl3(THF)1,8 reacts with Na[pyr*
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Ephedrine-Derived Imidazolidin-2-ones. Broad Utility Chiral Auxiliaries in Asymmetric Synthesis (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2663-2673 
    Details
    ISSN: 0009-2940
    Keywords: Imidazolidin-2-one, (4R,5S)-1,5-dimethyl-5-phenyl- or cyclohexyl- ; (-)-Ephedrine ; Stereoselective aldol ; alkylation, acylation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The scope of the readily available (4R,5S)-1,5-dimethyl-4-phenylimidazolidin-2-one (4) and its 4-cyclohexyl analogue 6 as practical, efficient chiral auxiliaries has been demonstrated. The enolate chemistry of their N-acyl derivatives exhibits features which recommend their use in asymmetric synthesis. The stereoselective boron-mediated aldol as well as alkylation and acylation results are presented. The steric control benefit derived by conversion of phenyl to cyclohexyl is highlighted.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261216
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Gas-Phase Thermolysis of Pyrazolines, 2[1]. Electronic Structure and Gas-Phase Thermolysis of 4,5-Dihydro-3H-pyrazoles Studied by Photoelectron Spectroscopy, Semiempirical Quantum-Chemical Calculations, and Flash Vacuum Pyrolysis (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2675-2681 
    Details
    ISSN: 0009-2940
    Keywords: Electronic structure ; PE spectroscopy ; Gas-phase thermolysis ; 3H-Pyrazoles, 4,5-dihydro- ; 1,3,4-Oxadiazole, 2,5-dihydro- ; 1,3,4-Thiadiazole, 2,5-dihydro- ; Cyclopropanol, 2,2,3,3-tetramethyl- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The PE spectra of the 4,5-dihydro-3H-pyrazoles 1, 2, of 2,5-dihydro-1,3,4-oxadiazole 3, and 2,5-dihydro-1,3,4-thiadiazole 4 have been recorded. Based on HAM/3, MNDO, AM1, and PM3 calculations, the ionization potentials have been assigned to molecular orbitals. The gas-phase thermolyses of 1-4 have been studied by PE-controlled gas analysis. Extrusion of molecular nitrogen leads to reactive species which cyclize to three-membered rings of different stability. At higher temperatures and in flash vacuum pyrolysis, consecutive reactions may lead to smaller acyclic molecules. The cyclo-propanol 7, obtained by denitrogenation of 2, is thermally rather stable. Its PE spectrum has been recorded and analyzed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261217
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Photochemical and Thermal Rearrangement of Acyl-Substituted Quinone Methides, Accessible by Dimethyldioxirane Oxidation of Benzofurans and Subsequent Valence Isomerization of the Resulting Epoxides (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2697-2699 
    Details
    ISSN: 0009-2940
    Keywords: Epoxidation ; Dioxirane, dimethyl- ; Benzofurans, 2-methyl-3-phenyl ; Benzofuran epoxides ; Quinone methides ; (Z/E) Photoisomerization ; Norcaradiene ; Benzocycloheptafuran ; Thermal rearrangement ; Xanthenes, 9-acetyl- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photoisomerization of quinone methides 3 to benzocycloheptafuran 4 and the thermolysis of the latter to xanthenes 5 are reported. The quinone methides 3 are accessible by dimethyldioxirane oxidation and subsequent valence isomerization of the resulting benzofuran epoxides 2. On irradiation (λ 〉 400 nm), the quinone methides 3 rearrange by cyclization to the corresponding norcaradiene, and ring enlargement affords the benzocycloheptafurans 4. Thermolysis of the cycloheptatrienes 4 leads to the xanthenes 5, first by cycloreversion to the norcaradienes, followed by electrocyclization to the chromenes and tautomerization of the latter. The new cycloheptatrienes 4 and xanthenes 5 were fully characterized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261220
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Oxidative Spaltung von Poly(o1-phenylendiselenid) (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1071-1076 
    Details
    ISSN: 0009-2940
    Keywords: Selenium halogen compounds ; Poly(o1-phenylenediselenide), cleavage of ; Oxidative cleavage ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxidative Cleavage of Poly(o1-phenylenediselenide)Poly(o1-phenylenediselenide) is cleaved at the Se-Se bond by treatment with SOCl2 to give benzene-1,2-bis(selenenyl chloride) (2) and benzene-1,2-bis(selenium trichloride) (3), respectively. In the solid state 2 is dimerized by Se…Se bonds whereas 3 is monomeric having terminal as well as intramolecular bridging Cl atoms. Treatment of 2 with SbCl5 gives an ionic compound (4) with a dimeric cation exhibiting a weak Se—Se bond and SbCl6- as a counterion 3 reacts with W(CO)6 to give trigonal prismatic dicarbonyl bis(o1-phenylenediselenolato)tungsten (5).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Enantioselektive Katalyse, IX. Neue optisch reine 3,4-Bis(phosphanyl)pyrrolidine mit Phenyl-und Anisylgruppen sowie deren Palladium-und Rhodiumkomplexe (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1091-1100 
    Details
    ISSN: 0009-2940
    Keywords: 3,4-Bis(phosphanyl)pyrrolidines ; Palladium complexes ; Rhodium complexes ; Asymmetric hydrogenation ; Phosphanes, chiral ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Enantioselective Catalysis, IX[1]. - New Optically Pure 3,4-Bis(phosphanyl)pyrrolidines with Phenyl and Anisyl Groups Including Their Palladium and Rhodium ComplexesMethods for the synthesis of the diastereomeric mixture of the [P(R,S),3R,4R,P′(R,S)]1-1-(tert1-butoxycarbonyl)1-3,4-bis[(2-methoxyphenyl)phenylphosphanyl]pyrrolidines (2a, b, c) are described. For the chromatographic separation and purification of the ligand diastereomers we transformed them into the PdI21-complexes (10a, b, c). The structure of (PR,3R,4R,P′R)1-1-(tert1-butoxycarbonyl)1-3,4-bis[(2-methoxyphenyl)phenylphosphanyl]pyrrolidine-P,P′}diiodopalladium (10 b) was determined by X-ray diffraction. Treatment of the palladium complexes with KCN yielded the pure phosphanes. The rhodium complexes (11a, 11b, 11c), which can be used as catalysts in enantioselective hydrogenations, were obtained by reaction of [Rh(COD)2]BF4 with compound 2a, 2b, or 2c.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Organo-substituierte Silole durch zweifache Organoborierung von Di-1-alkinylsilanen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1107-1114 
    Details
    ISSN: 0009-2940
    Keywords: Dialkynylsilanes, intermolecular 1,1-ethyloboration of ; 1,1-Vinyloboration, intramolecular ; 3-Borylsiloles, protodeborylation of ; (Ligand)transition metal, η4 complexes of ; Sandwich complex, cyclodiastereomers of ; Siloles, boryl-organo-substituted ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organo-Substituted Siloles by Twofold Organoboration of Di-1-alkynylsilanesMe2Si(C≡CR)2 [R=Me (A), Bu (B), tBu (C), iPent (D), Ph (E), Me3Si (F)], prepared from Me2SiCl2 and MC≡CR (M=Li, Na, K), react with Et3B by 1,1-ethyloboration to form the organo-substituted siloles Me2 (1a - f) in high yields with different reaction rates: F 〉 B ≍ D 〉 A 〉 C 〉 E. Me2Si(C ≡CiPent)(C ≡ CPh) (H) and Et3B give a 5 : 1 mixture of the two regioisomeric substituted siloles 2 and 2′. - 1a and e are deborylated with H2NCH2CH2OH or MeCO2H to 3a and e, respectively. 1a reacts with maleic anhydride to yield the [4 + 2] addition compound 4a. With (OC)5Fe, Cp-Co(C2H4)2, and (CDT)Ni the cycloracemic (ligand)transition metal η41-complexes [(OC)3Fe-1a (5a), (OC)3Fe-3a (6a), CpCo-3a (7a)] and the cyclodiastereomeric η4,η41-complexes Ni-(3a)2 (8a/8a′) are formed. All products were characterized by multinuclear NMR, including measurements of J(29Si13C) and J(13C13C).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 217. [2 + 2]1-Cycloadditionsreaktionen von 9-Fluorenyliden-(tetramethylpiperidino)boran mit Carbonyl-und Thiocarbonyl-Verbindungen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1119-1125 
    Details
    ISSN: 0009-2940
    Keywords: Cycloaddition reactions ; 1,2-Oxaboretanes ; 1,2-Thiaboretanes ; 1,2-Azaboretidines ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 217[1]. - [2 + 2] Cycloaddition Reactions of 9-Fluorenylidene(tetramethylpiperidino)borane with Carbonyl and Thiocarbonyl CompoundsAmino-9-fluorenylidene-borane 1 reacts with acetone or benzophenone in a [2 + 2] cycloaddition manner to give stable 1,2-oxaboretane derivatives 2. Aldehydes behave similarly but the oxaboretanes formed decompose readily. The esters MeCO2Et and MeC≡C - CO2Me as well as Cp(CO)2Fe - COCH3 also provide access to novel oxaboretane derivatives (2e, f, h). In contrast, no oxaboretane is obtained from 1 and MeC(O)NMe2 and only (tmpBO)n (n=2, 3) was isolated as a decomposition product. The amides MeC(O)NHMe and MeC(O)NH2 also provide no access to cycloaddition since their NH bonds insert into the BC double bond of 1. Thioketones react with 1 to yield 1,2-thiaboretanes 5. Tetramethyl-cyclobutan-1-one-3-thione 8 adds 1 at its carbonyl function regiospecifically to form 9. No reaction between 1 and CO2 was observed, but COS produces an 1,2-oxaboretane-4-thione 7, and CS2 in the form of [CpFe(CO)2]2CS2 the corresponding 1,2-thiaboretane-4-thione 10. Analogously, the ketimine Ph2C=NMe adds to 1 producing the 1,2-azaboretidine 11. X-ray structure determination of the 1,2-oxaboretane 2h reveals a butterfly structure (folding anlge: 159.9°) of the four-membered ring in contrast to the 1,2-thiaboretane 5a whose four-membered ring is almost planar, the folding angle being 176.9°.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260509
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Repetitive-Synthesis of Bulky Dendrimers - A Reversibly Photoactive Dendrimer with Six Azobenzene Side Chains (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1161-1169 
    Details
    ISSN: 0009-2940
    Keywords: Azobenzene units ; Dendrimer ; Divergent synthesis ; Solvent inclusion ; Supramolecular chemistry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dendrimers with bulky repeating units containing up to 43 benzene rings (in 9) have been obtained by using a repetitive divergent synthetic strategy (three generations). The new functional dendrimer 13 containing six azobenzene units at the periphery was synthesized allowing a reversible switching of the shape and size of the molecule upon irradiation. An X-ray structure analysis of the dendritic molecule 3a shows the inclusion of acetonitrile.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260516
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Sterically Hindered Free Radicals, 21. 1,2- and 1,4-Additions of Diphenylmethyl Radicals to Substituted Acrylonitriles (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1179-1185 
    Details
    ISSN: 0009-2940
    Keywords: Radical additions ; Acrylonitriles ; Diphenylmethyl radicals ; Steric effects ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Additions of the substituted diphenylmethyl radicals Ar11-Ar2CR 2 (R=CMe3, SiMe3, GeMe3, SnMe3, OSiMe3, CF3, CO2Me, CN) to various acrylonitriles CH2=C(X)CN 3 (X=SMe, SiPr, StBu, OAc, OSiMe3, OSiEt3, OMe, OEt) lead to 1,2-5 or 1,4-adducts 6 (ketenimines), depending mainly on the steric hindrance by the substituents R and X. Bulky substituents like tBu in 2 and tBuS in the acrylonitrile favour the formation of the extended and nearly strainless ketenimine system 6 (1,4-adduct); smaller substituents like OSiMe3 (radical 2) and SMe, OAc, OSiMe3, OSiEt3, OMe, OEt (acrylonitrile) allow isolation of the sterically crowded 1,2-adducts. Substituents of intermediate bulkiness like CF3 (radical 2) and SiPr (acrylonitrile) give a mixture of 1,2-adducts (6cb, hb) and dimers 7 of the adduct radicals 4 (7cb, hb). The voluminous tBu group directly bound to the olefin (3j,k) prevents addition. The latter is generally reversible, and the various adducts 5, 6, or 7 dissociate to the adduct radicals 4 and/or fragment to the initial radicals 2 at temperatures which reflect the steric strains of the corresponding substituents R, X. The complete inertness, even toward the electron-rich olefin 3i, of the electrophilic α1-carbonyl-substituted radicals 2q - s (R=CHO, COMe, COPh) in the above additions is discussed. Additions of the radicals 2a - c, f, i, n, o to the conjugated olefin 3n are described and are in accordance with the conclusion that steric effects predominate in adduct formation, whereas electronic effects are of distinct but minor importance.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Stereoselektive Protonierung von Carbanionen, 1. Diastereoselektive Protonierung von C - H-aktivierten Cyclohexan-Derivaten (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1205-1215 
    Details
    ISSN: 0009-2940
    Keywords: Carbanions ; Protonation, diastereoselective ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The diastereoselectivity of the kinetically controlled protonation of carbanions derived from 4-tert1-butyl-1-X-cyclohexanes (1: X=CN, 2: X=CO2Me, 2-Si: X=C(OMe)OSiMe3, 3: X=COPh, 4: X=SO2Ph) is systematically investigated. By variation of (a) the base for deprotonation of 1 - 4, (b) OH-, NH-, and CH-proton sources, (c) added salts, Lewis bases, and acids, (d) solvents (cf. Tables 2 - 5) the cis/trans ratios of diastereomers could be influenced as follows: 1: 41/59→85/15; 2: 26/74→73/27; 3: 26/74→〉93/〈3; 4: 1/99→37/63. The results are discussed with regard to structure and aggregation of 1Li to 4Li and compared with relevant data from the literature. It is concluded that so far an empirical approach to high diastereoselectivities cannot be avoided and that the results cannot be predicted from the ratios obtained by the much slower alkylation reactions.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260522
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Synthesis of Alkyl-Substituted Helianthrones and Mesonaphthobianthrone by Highly Regioselective Photocyclization of Bianthronylidenes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1217-1225 
    Details
    ISSN: 0009-2940
    Keywords: Bianthronyls ; Bianthronylidenes ; Helianthrone ; Mesonaphthobianthrone ; Photocyclization ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the novel alkyl-substituted helianthrones 8a, c and mesonaphthobianthrone 9 by photocyclization of the corresponding bianthronylidenes 7a, b is described. Regioselectivity and scope of the photocyclizations of 7a and 7b depend on the substitution pattern. The structures of 7a and 8a have been established by X-ray crystallography and indicate an isomerization about the central double bond of 7a in the photoreaction. The structures of the protonated species of 8a and 9 are elucidated, and their optical absorption and emission behavior is examined.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Rate-Determining Effects in the Formation of Hantzsch 1,4-Dihydropyridines from N-(1-Haloalkyl)azinium Halides and Methyl 3-Amino-2-butenoate (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1251-1252 
    Details
    ISSN: 0009-2940
    Keywords: Azinium halides, N-(1-haloalkyl)- ; Pyridines, 1,4-dihydro- ; Rates of Formation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-(1-Haloalkyl)azinium halides react with methyl 3-amino-2-butenoate to yield 4-substituted dimethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylates. The rates of formation of the latter compounds are monitored by 1H-NMR spectroscopy. Mechanistic and practical considerations are discussed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260527
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Darstellung, Struktur und Eigenschaften von harnstoffverbrückten cyclischen Phosphoniumsalzen mit Phosphor-Phosphor-, Phosphor-Arsen-, Phosphor-Antimon-und Phosphor-Zinn-Bindung (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1271-1281 
    Details
    ISSN: 0009-2940
    Keywords: Phosphonium compounds ; Phosphorus-phosphorus bonds ; Phosphorus-arsenic bonds ; Phosphorus-tin bonds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation, Structure, and Properties of Urea-Bridged Cyclic Phosphonium Salts with Phosphorus-Phosphorus, Phosphorus-Arsenic, Phosphorus-Antimony, and Phosphorus-Tin BondsN-[tert1-Butyl(phenyl)phosphanyl]-N,N′-dimethyl-N′-(trimethylsilyl)urea (2) reacts with organodichlorophosphanes with cleavage of the Si - N bond to form the cyclic phosphanylphosphonium chlorides 3a - i containing the grouping [λ3P - λ4P+]Cl-. Evidence was obtained for the existence of an equilibrium in solution between the ionic phosphonium structure 3 and a covalent form. The position of the equilibrium is determined by the nature of the group R at λ3P. Reaction of the phosphonium salts 3a - i with Na[BPh4] furnished the phosphonium tetraphenylborates 4a - i containing the grouping [λ3P - λ4P+][BPh4]-. In the reaction of 2 with organodichloroarsanes the arsanyl-phosphonium chlorides 5a and 5b with the grouping [λ3As - λ4P+] were formed. By treatment of 5a and 5b with Na[BPh4] the corresponding tetraphenylborates 6a and 6b were produced. Further cyclic phosphonium salts containing a heteroatom-phosphorus bond with the complex chloro anions [AsCl4]-, [SbCl4]-, and [Me2SnCl4]2- were formed in the reaction of 2 with the chlorides AsCl3, SbCl3 and Me2SnCl2. - The structures of 4h and 6a were confirmed by low-temperature X-ray crystal structure determination; the P - P bond length of 4h is 222.3(2) pm, the P - As bond length of 6a 234.6, 234.1(2) pm in two independent cations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260603
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Trimethylsilylcyanid als Umpolungsreagens, XXIII. Umpolungsprodukte aus α,β1-ungesättigten Aldehyden mit α,β1-ungesättigten Carbonyl-Verbindungen: Folgereaktionen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 997-1001 
    Details
    ISSN: 0009-2940
    Keywords: Umpolung ; Michael addition ; 1,4-Diketones ; ∊1-Keto esters ; Cyclopentanes ; Cyclopentenones ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Trimethylsilyl Cyanide - A Reagent for Umpolung, XXIII[1]. - Products from Umpolung of α,β1-Unsaturated Aldehydes and α,β1-Unsaturated Carbonyl Compounds: Consecutive ReactionsThe unsaturated nitrile 1 is transformed by TiCl4 into chloronitrile 2, whereas reaction with [BzNMe3]+F- and treatment with acids yields cyanocyclopentenone 4. Removal of the umpolung groups from 1 and 5-8 by [BzNMe3]F- results in the unsaturated 1,4-diketones 9-13 only if the cyanide ions formed are prevented by ZnO from adding to the double bond. Condensation of ketones 9 and 11-13 with tBuOK yields cyclopentenones 14-18 with conjugated vinylic groups. In the presence of [BzNMe3H]+F- α1-cyano enol silyl ethers 22-24 are smoothly converted in methanol into ∊1-oxo-carboxylic esters 19-21, whereas in pure methanol α1-hydroxycyclopentanecarboxylic esters 25-27 are produced in high yied.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260420
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Bimolekulare Radikalbildung durch H-Transfer, 2. H-Transferreaktionen mit Phenalen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1039-1045 
    Details
    ISSN: 0009-2940
    Keywords: Hydrogen transfer ; Radical formation, molecule induced ; C—H bond dissociation enthalpies, determination of ; Catalysis ; Coal pyrolysis ; Phenalene ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bimolecular Formation of Radicals by H-Transfer, 2[1]. - H-Transfer Reactions of PhenaleneThe uncatalysed H transfer from phenalane (7) to α1-methyl-styrene (2) and the selfreaction (d) of phenalene (7) are quantitative transformations in the presence of an excess of 9,10-dihydroanthracene (1) (DHA) in diphenyl ether at 200-250°C. In this system phenalene (7) is consumed only in reaction (d) because the phenalenyl radicals (9) are captured by DHA (1) to give phenalene (7) and 9,10-dihydroanthryl radicals (3). The latter disproportionate rapidly. Accordingly, phenalene (7) acts as a catalyst for the hydrogenation of α1-methylstyrene (2) by DHA (1). The activation parameters of the two reactions (e) and (d) were obtained from kinetic experiments between 200-250°C. They allow the determination of the C—H bond enthalpy δHdiss of phenalene (7) (65.3 kcal mol-1) at the methylene position.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260426
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Synthesis of Isomerically Pure Organodihydrofullerenes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1061-1067 
    Details
    ISSN: 0009-2940
    Keywords: Buckminsterfullerenes ; Organodihydrofullerenes ; Fullerene derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Controlled two-step nucleophilic hydroalkylations, hydroar-ylations as well as hydrostannylations of fullerene-60 (1) and fullerene-70 (2) lead to defined organodihydrofullerenes C60HR and C70HR. NMR investigations show that only one isomer of each organodihydrofullerene with Cs symmetry is formed. In all cases the addition takes place at a double bond separating two six-membered rings of the fullerene core. In this way a variety of organodihydrofullerenes also carrying functional groups have been synthesized.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260428
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Syntheses and Structures of Transition-Metal Complexes of Mesoionic Olate, Thiolate, Selenolate, and Cyclopentadienide (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1157-1159 
    Details
    ISSN: 0009-2940
    Keywords: Mesoionic compounds ; Transition metal complexes ; Tetrazolium-4-olate,-4-thiolate,-4-selenolate-, 4-cyclo-pentadienide, complexes with molybdenum or chromium carbonyls ; 1,2,4-Triazolium-3-thiolate, complex with pentacarbonylmolybdenum ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dicarbonyl(η1-cyclopentadienyl)iron(II) complex 5 of 1,3-diphenyltetrazolium-5-olate (4) and the pentacarbonylmolybdenum(0) complexes 7, 11, and 9 of 1,3-diphenyltetrazolium-5-thiolate (6), -5-selenolate (10), and 5-methyl-1,4-diphenyl-1,2,4-triazolium-3-thiolate (8) as well as tricarbonylchromium(0) complex 13 and -molybdenum(0) complex 14 of 1,3-diphenyltetrazolium-5-cyclopentadienide (12) have been prepared. Their physicochemical properties are discussed on the basis of spectroscopic properties.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260515
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Complexation with Diol Host Compounds, 12. Synthesis and Solid-State Inclusion Properties of Bis(diarylhydroxymethyl)1-Substituted 1,1′-Binaphthyls. Crystal Structures of a Host and Its Pyridine Clathrate (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1141-1148 
    Details
    ISSN: 0009-2940
    Keywords: Diol host compounds ; Clathrates ; Crystal structures of host and clathrate ; 1,1′-Binaphthyl derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of new clathrate host molecules 1 - 8 containing two bis(diarylhydroxymethyl) groups attached to different positions (2,2′ or 8,8′) of a 1,1′-binaphthyl frame have been synthesized. Their clathrate formation properties with organic guests including alcohols, amines, ketones, and other dipolar aprotic compounds or aromatic hydrocarbons are reported (74 examples of clathrates) together with the results of solvent competition experiments for the parent host compound. The inclusion formation and the clathrate stoichiometries depend on the structure of the host molecules in a systematic manner. The crystal structures of the free parent host 1 and its pyridine clathrate (1 : 3) have been determined by X-ray diffraction. The molecular structure of the host is similar in the two species involving an intramolecular hydrogen bond between the host hydroxyls. No other hydrogen bond is involved in the free host case while in the pyridine inclusion compound the second host hydroxyl forms a hydrogen bond with the nitrogen of one pyridine guest which is surrounded by two unbound pyridine species such as to form clusters of three pyridine guests enclosed in the cavities between the host molecules. Thermal analysis corresponds with the two binding states of the pyridine molecules in the clathrate.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    (Di-tert1-butylfluorsilyl)hydrazin, ein Baustein für strukturisomere N,N- und N,N′1-Bis(silyl)hydrazineHerrn Professor Heinrich Nöth zum 65. Geburtstag gewidmet. (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1413-1416 
    Details
    ISSN: 0009-2940
    Keywords: Hydrazine, N-(fluorosilyl)- ; Condensation ; Cyclization ; Bis(silyl)hydrazines ; Isomerism, structural ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Di-tert1-butylfluorosilyl)hydrazine, a Building Block for Structure-Isomeric N,N- and N,N′1-Bis(silyl)hydrazinesDi-tert1-butyldifluorosilane reacts with monolithiated hydrazine to give the stable monosilylated hydrazine 1 and the six-membered ring 2. The bis(fluorosilyl)hydrazine 3 is formed in a condensation reaction by heating 1 at 220°C. HCl elimination between 1 and chlorosilanes leads to the N,N′1-disubstituted hydrazines 4 and 5. An N,N′1-bis(silyl)hydrazine 6 is obtained in the reaction of lithiated 1 with difluorodiisopropylsilane while an N,N1-bis(silyl)hydrazine 7 is formed with tert1-butyltrifluorosilane. Structural isomerism (8-11) is observed in reactions of lithiated 1 with [(trifluorosilyl)amino]silanes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Novel Spherand-Type Calixarenes - Synthesis, Conformational Studies, and Isomer Separation (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1435-1439 
    Details
    ISSN: 0009-2940
    Keywords: [1n]Metabiphenylophanes, hydroxy- ; Calixarenes ; Conformation ; Hydrogen bonding, intramolecular ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The novel macrocyclic compounds hexahydroxy[1.0.1.0.1.0]-6b and octahydroxy[1.0.1.0.1.0.1.0]metacyclophane 6c have been prepared in 50-70% yield by base-catalyzed condensation of 5,5′-di-tert1-butyl-2,2′-dihydroxybiphenyl (5) with formaldehyde in xylene. The conformations of trimer 6b and tetramer 6c have been evaluated from their dynamic 1H-NMR spectra. Methylation of the hydroxyl groups of 6b and 6c with MeI gives the corresponding methoxy[1n]metabiphenylophanes 7b and 7c in good yields. The metacyclophane 7b has been found to consist of two isomers, out of which one was separated pure. The structural characterization of these products is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260625
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Masthead (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Tripodal Triamidostannates as Building Blocks in the Generation of Sn - M-Bonded Heterobimetallics (M = Fe, Ru) (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 29-34 
    Details
    ISSN: 0009-2940
    Keywords: Tripodal ligands ; Triamidostannates ; Metal-metal bonds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By in situ lithiation of the trifunctional amines H3CC(CH2NHSiMe3)3, PhC(CH2NHSiMe3)3, and HC{SiMe2NH(p-Tolyl)}3 and subsequent reaction with SnCl2 the corresponding triamidostannates were obtained. These were coupled with CpM(CO)2Cl (M = Fe, Ru) to yield the M - Sn-bonded heterobimetallics 9-14 of which H3CC(CH2NSiMe3)3SnFe(CO)2Cp (9) was characterized by a single-crystal X-ray structure analysis. Of the in situ-generated amidostannates only [HC{SiMe2N(p-Tolyl)}3Sn][Li(THF)3] (8) could be isolated as a uniform product and characterized analytically and spectroscopically.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    The Structures of [X2Y—N—YX2]+ Cations (X = F, Cl; Y = S, Se). A Comparison of X-ray and ab Initio Studies[1] (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 35-40 
    Details
    ISSN: 0009-2940
    Keywords: Selenium-nitrogen compounds ; Sulfur-nitrogen compounds ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structures of cationic species of the series [X2Y—N—YX2]+ (X = F, Cl; Y = S, Se) have been computed ab initio using all electron treatments for first-row elements and sulfur and quasi-relativistic pseudopotentials for Se and Cl. Splitvalence basis sets with polarization and diffuse functions were employed. The MP2 results for the (non-isostructural!) cations [Cl2Se—N—SeCl2]+ (1: Cs) and [F2S—N—SF2]+ (2: C2v) are in excellent agreement with the experimental (X-ray) observations. Both structures represent local minima. A deeper minimum for either of the cations is represented by another C2v isomer which for crystal lattice energy reasons is stable in the isolated state only. The geometries of the hitherto unknown species [Cl2S—N—SCl2]+ (3) and [F2Se—N—SeF2]+ (4) have been assessed by ab initio HF calculations. In analogy to 2, cations 3 and 4 are predicted to prefer C2v symmetry. Therefore, 1 exhibits unusual structural features. According to strictly localized natural bond orbital analysis (NBO), the central nitrogen atoms in 1 and 2 possess two lone pairs of electrons (LP: one sp hybrid and one p orbital). The relatively short Se—N and S—N bond distances in 1 (1.741-1.760 Å) and 2 (1.551 Å) can best be attributed to LP(N)→s̰*(Y—X) negative hyperconjugation (1: Y = Se, X = Cl; 2: Y = S, X = F).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Die fördernde Rolle von Phosphinoester-Liganden bei der Synthese neutraler Carben-, Vinyliden- und Allenyliden-Ruthenium(II)-KomplexeHerrn Professor Hubert Schmidbaur zum 60. Geburtstag gewidmet. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 49-62 
    Details
    ISSN: 0009-2940
    Keywords: Ruthenium(II) complexes, octahedral ; Phosphino esters as mono- and bidentate ligands ; Fluxional behaviour ; Carbene complexes ; Vinylidene complexes ; Allenylidene complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinylidene Transition-Metal Complexes, XXXV[1].  -  The Supporting Role of Phosphino Ester Ligands for the Synthesis of Neutral Carbene, Vinylidene and Allenylidene Ruthenium(II) ComplexesThe reaction of [RuCl2(PPh3)3] (1) with the phosphino esters iPr2P(CH2)nCO2R (2-4) leads to complete (n = 1; R = CH3, C2H5) or partial (n = 2; R =CH3) displacement of the PPh3 ligands and formation of the octahedral ruthenium(II) complexes [RuCl2{k2(P,O)-iPr2PCH2CO2R}2] (5, 6) and [RuCl2(PPh3){k(P)-iPr2PCH2CH2CO2Me}{k2(P,O)-iPr2PCH2CH2CO2Me}] (7). Treatment of 5 with LiBr and LiI affords the dibromo- and diiodoruthenium derivatives 8 and 9. While compound 5 reacts with CO and SO2 by cleavage of one Ru - O bond to yield the 1:1 adducts [RuCl2(L){k(P)-iPr2PCH2CO2Me}{k2(P,O)-iPr2PCH2CO2Me}] (10, 11), the reaction of the dibromo derivative 8 with CO in solution gives the dicarbonyl complex [RuBr2(CO)2{k(P)-iPr2PCH2CO2Me}2](13). If CO is passed over 8 in the solid state, the corresponding monocarbonyl compound 14 is formed. The hydridoruthenium(II) complex 16, which is obtained from equimolar amounts of [RuHCl(CO)(PiPr3)2] (15) and 2, reacts with HC≡CMe by insertion to give the vinyl derivative [RuCl{E - CH=CHMe}(CO)(PiPr3){k2(P,O)-iPr2CH2CO2Me}] (17). Treatment of 5 with HC̊' (R' = H, Me, tBu, Ph) and of 6, 8, 9 with HC≡CPh affords upon photochemical activation the octahedral vinylidene complexes [RuX2-(=C=CHR){k(P)-iPr2PCH2CO2R}{k2(P,O)-iPr2PCH2CO2R}] (18-21 and 23-25) in good to excellent yield. At room temperature, these compounds (with the exception of 25) are highly fluxional in solution. From 31P-NMR measurements, the free energies of activation ΔG
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Reaktionen von R2Al—AlR2 (R = CH(SiMe3)2) mit Trimethylsilylazid  -  Insertion in die Al—Al-Bindung und Abbau zum trimeren Dialkylaluminiumazid (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 81-85 
    Details
    ISSN: 0009-2940
    Keywords: Aluminium-aluminium bond ; Insertion of trimethylsilyl azide ; Trimeric dialkylaluminium azide ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of R2Al—AlR2 (R = CH(SiMe3)2) with Trimethylsilyl Azide  -  Insertion into the Al—Al Bond and Formation of a Trimeric Dialkylaluminium AzideTetrakis[bis(trimethylsilyl)methyl]dialuminium(4) (1) reacts with trimethylsilyl azide under insertion of one nitrogen atom into the Al—Al bond. As shown by NMR spectra and crystal structure the product contains three and four coordinated Al atoms due to the coordination of the α-nitrogen atom of the azide group to one of the Al atoms. An electronically delocalized N3-system is formed with a N—N bond length of 132.0 pm and a bond order of 1.5 for both N—N bonds. With an excess of trimethylsilyl azide further reaction is observed only under mild irradiation conditions with an exchange of the azide group between Si and Al and formation of Me6Si2 and the dialkylaluminium azide 3, which is better synthesized by the reaction of Me3Si—N3 with Cl—Al[CH(SiMe3)2]2. The sterically highly shielded aluminium azide 3 is a trimer in the solid state showing a non-planar 12-membered Al3N9 heterocycle with short N—N bonds (114 pm).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Transition-Metal Complexes with the Novel Scorpionate Ligand Dihydrobis-(tetrazolyl)borate: Synthesis and Characterization of Infinite Two-Dimensional Metal-Ligand Frameworks and One-Dimensional Water SubstructuresDedicated to Professor Dr. Herbert Schumann on the occassion of his 60th birthday. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 323-328 
    Details
    ISSN: 0009-2940
    Keywords: Poly(azolyl)borates, metal complexes of ; Bis(tetrazolyl)borate, metal complexes of ; Metal-nitrogen coordination ; Coordination polymers ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dihydrobis(tetrazolyl)borate metal compounds of the composition [M(L)2{μ-H2B(CHN4)2}2]n for M = Mn, Fe, Co, Zn, Cd with L = H2O and for M = Cu with L = NH3 are obtained from metal salts and K[H2B(CHN4)2]. Single-crystal X-ray studies reveal the formation of two-dimensional rhombic grid sheets through the bridging action of the bis(tetrazolyl)borate ligands. Each metal atom is octahedrally coordinated with two trans L ligands and four H2B(CHN4)-2 nitrogen donors. Two additional, hydrogen-bonded water molecules occupy the rhombic openings in the compounds with M = Mn, Fe, Co, Zn, and Cd. The water of crystallization is held in place through hydrogen bonding from the water ligands and to the nitrogen atoms to give a substructure of parallel kinked water chains. Temperature-variable magnetic measurements show a Curie-Weiss behavior for the paramagnetic complexes with M = Mn, Fe, Co, and Cu.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    New Organophosphorus Ligands: Cyclopropanation and Other Reactions of Cumulenes Bearing Diphenylphosphanyl Substituents (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 365-371 
    Details
    ISSN: 0009-2940
    Keywords: Cumulenes ; Butadienes ; Vinylcyclopropane ; Vinylidenecyclopropane ; Bicyclopropyl, phosphanyl-substituted ; Cyclopropanation ; Phosphane ligands ; Phosphane chalcogenides ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hydrophosphorylation of 1,4-bis(diphenylphosphanyl)butadiyne with diphenylphosphane leads to the butadiene (Ph2P)2C=CH—CH=C(PPh2)2 (1). Treatment of 1 with dimethylsulfonium methylide gives the vinylcyclopropane (Ph2P)2C=CH—CH(CH2)C(PPh2)2 (2). Compound 2 reacts with aqueous hydrogen peroxide, elemental sulfur, or selenium to afford the tetrachalcogenides (Ph2XP)2C=CH—CH(CH2)C(PXPh2)2 with X = O (3), X = S (4), X = Se (5), respectively. While the tetraphosphane 1 and the vinyl-cyclopropane compound 2 cannot be converted into a bis-(cyclopropyl) compound with an excess of Me2S=CH2, the tetrasulfide 4 readily affords a mixture of (1R,1′R)-/(1S,1′S)-and meso-2,2,2′,2′-tetrakis(diphenylthiophosphinyl)-1,1′-bicyclopropyl (6, 7) in good yield. Treatment of 1,1,4,4-tetrakis-(diphenylphosphanyl)butatriene with dimethylsulfonium methylide leads to the vinylidenecyclopropane (Ph2P)2C=C=C(CH2)C(PPh2)2 (8). Compound 8 is converted into its tetrasulfide (Ph2SP)2C=C=C(CH2)C(PSPh2)2 (9) by treatment with elemental sulfur. The crystal structures of 1, 2, 4, 7, and 8 have been determined by single-crystal X-ray diffraction.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280408
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Mono- und Diferriophosphane und -thioxophosphoraneHerrn Professor Dr. Ekkehard Lindner zum 60. Geburtstag gewidmet. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 413-416 
    Details
    ISSN: 0009-2940
    Keywords: Ferriophosphanes ; Ferriophosphoranes ; Thioxophosphane ligand ; Decarbonylation reaction ; Sulfurization ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mono- and Diferriophosphanes and -thioxophosphoranesHerrn Professor Dr. Ekkehard Lindner zum 60. Geburtstag gewidmet.The substitution of organic substituents in phosphanes or thioxophosphoranes by the 17-electron fragments CpFe-(CO)2 (—Fp) leads to isolobal ferriophosphanes or -thioxophosphoranes. The mono- and diferriophosphanes FpnPPh3-n [n = 1 (3), 2 (4)] are obtained by deprotonation of the mono- and diferriophosphonium salts [FpnPPh3-nH]X [n = 1 (1), 2 (2)] with DBU. They are oxidized by sulfur giving the mono- and diferriothioxophosphoranes FpnPPh3-n(S) [n = 1 (5), 2 (6)]. Sulfide 5 arises also from the reaction of CpFe(CO)2Cl and Ph2PH(S)/DBU. The one-sided decarbonylation reaction of 6 leads to FpFp′PPh(S) (7, Fp′ = CpFeCO). The Fp substituents (17 electrons) in 3-7 coordinate as one-electron donors to the PhnP- or PhnP(S) units (n = 1, 2). The bridging functions in 4 and 6 are hitherto unknown. The molecular structures of the complexes 5-7 were determined by X-ray structure analyses.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280413
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    About some Electrophilic Substitution Reactions with [(CF3S)3C+][AsF-6] (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 435-436 
    Details
    ISSN: 0009-2940
    Keywords: Trifluoromethylthio group ; Carbenium ions ; Diphenylmethane ; Dyes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tris(trifluoromethylthio)carbenium hexafluoroarsenate (1) reacts with N,N-dimethylaniline and anisole to form the corresponding diphenylmethanes 2, 3 with the SCF3 group at the methine carbon atom. During the reaction of 1 with benzene, compounds such as C6H5C(SCF3)3 and C6H5SCF3 are formed along with benzophenone, a product of hydrolysis of the diphenylmethane compound.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280417
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Synthesis and Structure of the First Dimetalated Diphosphane Disulfide [(η5-C5Me5)(CO)2FeP(H)(S)]2 (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 441-442 
    Details
    ISSN: 0009-2940
    Keywords: Diphosphane disulfides ; Metallophosphoranes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The first transition metal derivative meso-[(η5-C5Me5)(CO)2FeP(H)(S)]2 (2) of the unknown diphosphane disulfide [PH2(S)]2 results from treatment of (η5-C5Me5)(CO)2FePH2 (1) with 1.5 equivalents of elemental sulfur. Compound 2 was characterized by means of spectroscopy (IR, 31P, 31P{1H}, 13C{1H}, 1H NMR) as well as X-ray diffraction analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280419
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Preparation and Molecular Structures of Tetrahydrofuran, Diethylene Diglycol Dimethyl Ether and 18-Crown-6 Complexes of Strontium and Barium TetrahydridoborateDedicated to Prof. Dr. Nils Wiberg on the occasion of his 60th birthday. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 455-460 
    Details
    ISSN: 0009-2940
    Keywords: Strontium bis(tetrahydridoborate)-2 tetrahydrofuran, chain polymer of ; Strontium bis(tetrahydridoborate)-bis(diglyme) ; Barium bis(tetrahydridoborate)-bis(diglyme) ; Strontium bis(tetrahydridoborate)-1,4,7,13,16-hexaoxacyclooctadecane ; Metal-hydrogen-boron bridges ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The strontium and barium tetrahydridoborate complexes M(BH4)2 · 2 diglyme and M(BH4)2 · 18-crown-6 (M = Sr, Ba) have been prepared from the solvates M(BH4)2 · 2 THF by ligand displacement. 11B-NMR and IR data reveal strongly polar bonding of the BH4 groups to the metal centers, and X-ray structural analyses of the diglyme and crown ether compounds show molecular units in which the BH4 group is in contact via three H atoms with the metal center. In contrast, M(BH4)2 · 2 THF compounds are chain polymers in the solid state, and each metal center is surrounded by 2 THF molecules in trans position and four BH4- groups each of which forms bridges with two metal centers. Estimations of the effective radius for the BH4 group indicate a high polarity for the M-BH4 interaction.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Photochemische Reaktionen von Übergangsmetall-Organyl-Komplexen mit Olefinen, 1312. Mitteilung: Lit.Photochemisch induzierte [5+2],homo[5+21-Cycloaddition von 3-Hexin an Tricarbonyl(η5-2,4-cycloheptadien-l-yl)mangan (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 515-518 
    Details
    ISSN: 0009-2940
    Keywords: Manganese ; Cycloheptadienyl ; Alkyne ; [5+2],homo[5+2] Cycloadditions ; Tricyclo[5.3.1.04,10]undeca-2,5-dien-11-yl ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical Reactions of Transition Metal Organyl Complexes with Olefins, 1312. Mitteilung: Lit. . - Photochemically Induced [5+2], homo[5+2] Cycloaddition of 3-Hexyne to Tricarbonyl(η 5-2,4-cycloheptadien-1-yl)manganeseTricarbonyl(η5-2,4-cycloheptadien-1-yl)manganese (1) reacts upon UV irradiation in hexane at 243 K with two equivalents of 3-hexyne (2) in successive [5+2],homo[5+2] cycloadditions to give tricarbonyl(η2:2:1-1,2,3,11-tetraethyltricyclo-[5.3.1.04,10]undeca-2,5-dien-11-yl)manganese (3). Its crystal and molecular structure was determined by an X-ray diffraction analysis, in solution it was studied also by IR and NMR spectroscopy.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Masthead (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280601
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    1,4,2-Diazaphospholothiazoles and -pyridines by a Hantzsch-Type Condensation Using Chloromethyldichlorophosphane (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 581-587 
    Details
    ISSN: 0009-2940
    Keywords: Anellated azaphospholes ; Hantzsch-type [3 + 2] cyclocondensation ; Chloromethyldichlorophosphane ; Regioselectivity ; 31P-, 1H-, 13C-NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The [3 + 2] cyclocondensation of 2-amino-1,3-thiazoline, 2-aminopyridines, 2- and 4-aminopyrimidines, 2-aminopyrazine, and 2-aminoquinoline with chloromethyldichlorophosphane in the presence of triethylamine yields regiospecifically 5,6-dihydrothiazolo[2,3-e][1,4,2]diazaphosphole (3), 1,4,2-diazaphospholo[4,5-α]pyridines (12), 1,4,2-diazaphospholo[4,5-α]pyrimidines (15), 1,4,2-diazaphospholo[4,5-e]pyrimidine (17), 1,4,2-diazaphospholo[4,5-α]pyrazine (19), and [1,4,2]diazaphospholo[4,5-α]quinoline (22), respectively. Using 2-amino-1,3-thiazole (4) and 2-aminobenzothiazoles 8, we obtained mixtures of the 1,5- and 4,5-anellated 1,4,2-diazaphospholes 5/6, 9a/10a and 9b/10b, while in the case of the methyl derivative 8c only the [1,4,2]diazaphospholo[5,4-b][1,3]benzothiazole 10c was formed. In the reaction of 2-aminothiazole and 2-aminopyrazine with Chloromethyldichlorophosphane the bis(diazaphospholo)-substituted chloromethylphosphanes 7 and 20 could be detected. The new anellated 1,4,2-diazaphospholes are colorless to pale yellow crystalline moisture-sensitive solids.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280610
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Reactions at Silicon-Silicon Bonds, V. Selective Trichlorosilylation of Alkyl(diorganylamino)chlorophosphanes with Hexachlorodisilane or with Trichlorosilane/Triethylamine. - Two Routes to New Functional Trichlorosilylphosphanes (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 615-619 
    Details
    ISSN: 0009-2940
    Keywords: Reductive silylation ; Aminochlorophosphanes ; Silylphosphanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of alkyl(diorganylamino)chlorophosphanes R(R2′N)PCl 1 (1a: R = tBu, R′ = Et, 1b: R = iPr, R′ = iPr; 1c: R = iPr, R′ = Ph) with hexachlorodisilane, afforded alkyl(diorganylamino)trichlorosilylphosphanes R(R2′N)PSiCl3 2 (2a: R = tBu, R′ = Et; 2b: R = iPr, R′ = iPr; 2c: R = iPr, R′ = Ph) and silicon tetrachloride. An intermediate formed in the reaction of 1b with hexachlorodisilane, the adduct iPr(iPr2N)(Cl)P-Si(Cl)3-SiCl3 (3b = 1b · Si2Cl6), was detected by 31P- and 29Si-NMR spectra that indicate pentacoordinated silicon bound to tetracoordinated phosphorus and tetracoordinated silicon. Trichlorosilylphosphanes 2 are also available from 1 under very mild conditions by reductive trichlorosilylation with trichlorosilane in the presence of triethylamine. Compounds 2 were identified analytically, by mass spectroscopy, multinuclear NMR, and an X-ray structure determination of 2c.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280614
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Reactions of Complex Ligands, LXIVPart LXIII: Ref.. Synthesis of 5,5′-Diphenyl-2,2′-bifuran, a Biaryl Compound with Remarkable Fluorescence Properties (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 641-643 
    Details
    ISSN: 0009-2940
    Keywords: Carbene ligands ; Tungsten complexes ; 2,2′-Bifuran ; Copper coupling reaction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 2-oxacyclic α,β-unsaturated carbene complex 1 reacts with an excess of dimethylamine to give the diphenylbifuran 2. The structure of 2 was established by independent synthesis from 2-phenylfuran (4) via regioselective lithiation and transmetalation to zinc and tin organometallics 6a-c and final oxidative copper coupling reactions.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280618
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Synthesis of 2- and 3-Stannolenes via Addition of Trimethyltin Alkoxides to 3-Diethylboryl-4-ethyl-1,1-dimethylstannole (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 679-687 
    Details
    ISSN: 0009-2940
    Keywords: Stannole, diethylboryl-substituted ; Trimethyltin alkoxides ; 2-, 3-Stannolenes, organometallic-substituted ; NMR, coupling constants, 2J(Sn,Sn), sign determination ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Trimethyltin alkoxides (2) react stereoselectively with 3-diethylboryl-4-ethyl-1,1-dimethylstannole (1) via addition of the Me3Sn group to C(2) to the C(2) = C(3) bond and a 1,2 shift of an ethyl group from boron to C(3) to give the 2-stannolenes 3. The molecular structure of 3f' [R = (S)-2-Bu] was determined by single-crystal X-ray analysis, confirming the cis positions of the Et(RO)B and the Me3Sn group. These 2-stannolenes 3 undergo, upon heating to ca. 80°C, facile rearrangement by irreversible allylic migration of the Et(RO)B group to the 3-stannolenes 4 in which the cis positions of the boryl and the stannyl group are retained. All 2-stannolenes (in contrast to the 3-stannolenes) are readily deprotoborylated to give the 3-stannolene 5. The structures of 3, 4, and 5 follow conclusively from 1H-, 11B-, 13C-, and 119Sn-NMR spectra. The negative sign of the geminal coupling constants 2J(SnSn) was determined in the case of 3, 4, and 5 by 2D 119Sn/1H heteronuclear shift correlations.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280705
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Synthesis of Structures of (Acyloxy)boranesDedicated to Prof. Dr. A. Schmidpeter on the occasion of his 65th birthday.Synthesis of Structures of (Acyloxy)boranes (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 751-762 
    Details
    ISSN: 0009-2940
    Keywords: Trifluoroacyloxy-9-borabicyclo[3.3.1]nonane ; Pivaloyloxy-9-borabicyclo[3.3.1]nonane dimer ; Bis(9-borabicyclo[3.3.1]nonyl]oxalate ; Tetrakis(9-borabicyclo[3.3.1]nonyl)-dihydroxyoxalate ; Bis(9-borabicyclo[3.3.1]nonyl)-2,2-dimethylmalonate tetramer ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 9-Borabicyclo[3.3.1]nonane (9-BBNH) reacts with monocarboxylic acids to afford 9-(acyloxy)-9-borabicyclo[3.3.1]nonanes which are dimers in the solid state as shown by X-ray crystal structures of the benzoate and pivalate. More complex reactions were observed by allowing 9-BBNH to react with dicarboxylic acids in THF or monoglyme. Thus, (9-BBN)2 oxalate 3 contains a fully delocalized oxalate unit with equal C-O and B-O bond lengths. Traces of water convert it into the tetrakis(9-BBN) oxalate 5. A rather unusual structure is veryfied by 9-BBN 2,2-dimethylmalonate 7 which according to its molecular structure is a tetramer featuring a 32-membered ring system. In contrast, reactions of oxalic acid with thexylborane leads to reduction of the acid and formation of a bicyclic dioxaborolo-dioxaborolane 10. Several intermediates were detected by 11B-NMR spectroscopy as well as in reactions of BH3 · THF or BH3 · SMe2 with oxalic acid.  -  It follows from the present study that (acyloxy)boranes derived from dicarboxylic acids are strong Lewis acids with an unexpected variety of structural features.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280803
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    A T-Shaped Selenenyl Halide: Synthesis and Characterisation of a Proposed Reaction Intermediate (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 741-742 
    Details
    ISSN: 0009-2940
    Keywords: Selenenyl halides ; Nucleophilic substitution ; Complex intermediate ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The T-shaped selenenyl halide (1), which may be regarded as a model substance for the transition state in nucleophilic displacement at divalent chalcogen atoms, has been isolated and subjected to X-ray structure determination.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280715
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Zinc Complexes of Drugs Containing Nitrogen Heterocycles (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 779-785 
    Details
    ISSN: 0009-2940
    Keywords: Zinc complexes ; Drug ligands ; Captopril ; Isoniazid ; Nalidixic acid ; Mercaptopurine ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Four drugs whose actions have a relation to the status of zinccontaining species in the human body were used as ligands in zinc complexes. Captopril (H2Cap) forms the compound [ZnCap] (1) presumed to be a coordination polymer with O and S coordination. Isoniazid, in the presence of zinc salts, is converted to 1,2-diisonicotinoyl hydrazide (H2Nih) which forms polymeric [Zn(Nih)NH3] (2) with trigonal-bipyramidal ZnO2N3 coordination. Nalidixic acid (HNal) and zinc perchlorate yield [Zn(HNal)2(H2O)2](ClO4)2 · 2 H2O (3) containing zinc in an octahedral ZnO6 environment. Mercaptopurine (H2Mer), in the presence of ammonia, forms [Zn(Mer)(NH3)2] . H2O (4) which is a coordination polymer containing tetrahedral ZnN4 units. The structures of [Zn(Nih)NH3], [Zn(HNal)2(H2O)2](ClO4)2 . 2 H2O, and [Zn(Mer)(NH3)2] . 2 H2O were determined diffractometrically.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280807
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Enantioselective Deprotonation of Benzyl Phosphates by Homochiral Lithium Amide Bases  -  Configurational Stability of Benzyl Carbanions with a Dialkoxyphosphoryloxy Substituent and Their Rearrangement to Optically Active α-Hydroxy Phosphonates (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 823-830 
    Details
    ISSN: 0009-2940
    Keywords: Phosphate-phosphonate rearrangement ; Carbanions, benzylic, configurational stability of ; Phosphonaes Lithium amides, homochiral ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Benzyl dialkyl phosphates are deprotonated enantioselectively by homochiral lithium amides of isopropyl(1-phenylethyl)amine or bis(1-phenylethyl)amine. The short-lived benzylic carbanions formed are virtually configurationally stable relative to the rearrangement to optically active phenyl-hydroxymethylphosphonates. The enantiomeric excesses are up to 50%. The pro-(S) hydrogen is removed by amides having (S) configuration. Homochiral diethyl (S)-phenyl[D1]-methyl phosphate [(S)-16c] is deprotonated by both LDA and n-BuLi with a high primary kinetic isotope effect (kH/D ≍ 50) and isomerizes to the corresponding α-hydroxy phosphonate with an enantiomeric excess of up to 85%.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Tris(1,10-phenanthroline)iron(II) Complexes  -  Broad Variation of the Redox Potential by 4,7-Substitution at the Phenanthroline Ligands[1] (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 845-850 
    Details
    ISSN: 0009-2940
    Keywords: Phenanthroline synthesis ; Tris(phenanthroline)iron(II) complexes ; Redox potential ; Cyclic voltammetry ; Electron transfer, outer-sphere ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The new 4,7-donor-substituted phenanthrolines 2a-h were synthesized and the corresponding tris(1,10-phenanthroline)iron(II) complexes 3a-h studied by cyclic voltammetry. In more detail three novel aza-crown ether-linked (phenanthroline)iron complexes were investigated, the redox potentials of which could be fine-tuned by the addition of group-Ia,IIa metal cations. All iron(II) complexes showed reversible waves at scan rates between 50 and 500 mV · s-1 and could be reversibly oxidized and reduced by chemical means.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Bis(cyclopentadienyl)methane-Bridged Dinuclear Complexes, 10Part 9: B. Stempfle, H. Werner, Gazz. Chim. Ital., 1995, 125, in press. The Bis(cyclopentadienyl)methane Link between Lewis Basic and Lewis Acidic Metal CentersDedicated to Prof. Dr. Herbert Schumann on the occasion of his 60th birthday. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 877-881 
    Details
    ISSN: 0009-2940
    Keywords: Bis(cyclopentadienyl)methane ; Heterobimetallic complexes ; Imido complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mononuclear rhodium complexes [(C5H5CH2C5H4)-Rh(CO)2] (1) and [(C5H5CH2C5H4)Rh(PhC≡CPh)(PiPr3)] (2) readily react with nBuLi or TlOEt to yield the corresponding lithium salts 3 and 4 or thallium salts 5 and 6. The reaction of these salts with [(C5H5)Nb(NtBu)Cl2] (7) leads to the formation of the heterodinuclear compounds [{CH2(C5H4)2}-{Rh(CO)2}{(C5H5)Nb(NtBu)Cl}] (8) and [{CH2(C5H4)2}-{Rh(PhC≡CPh)(PiPr3)}{(C5H5)Nb(NtBu)Cl}] (9), respectively. Treatment of 3-6 with [Mo(NtBu)2Cl2] (10) gives the heterodinuclear Rh/Mo complexes [{CH2(C5H4)2}{Rh(CO)2}-{Mo(NtBu)2Cl}] (11) and [{CH2(C5H4)2}{Rh(PhC≡CPh)-(PiPr3)}{Mo(NtBu)2Cl}] (12). The analogous reaction of [Mo(NMes)2Cl2(DME)] (13) with 3-6 yields the corresponding complexes [{CH2(C5H4)2}{Rh(CO)2}{Mo(NMes)2Cl}] (14) and [{CH2(C5H4)2}{Rh(PhC≡CPh)(PiPr3)}{Mo(NMes)2Cl}] (15). From the monometallated ligand [(C5H5CH2C5H4)M] (M = Li: 16; M = Tl: 17) and the imidometal compounds 7, 10 and 13, the mononuclear complexes [(C5H5CH2C5H4)(C5H5)Nb-(NtBu)Cl] (18) and [(C5H5CH2C5H4)Mo(NR)2Cl] (R = tBu: 19; R = Mes: 20) have been obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951280905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Addition von Hydrofullerid [C60H]- an koordinierte, ungesättigte Kohlenwasserstoffe: Bindung von Fulleren an Metallkomplexe über KohlenwasserstoffbrückenHerrn Professor Herbert Walter Roesky zum 60. Geburtstag gewidmet (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1059-1060 
    Details
    ISSN: 0009-2940
    Keywords: Fullerene ; Hydrofulleride ; Manganese complex ; Rhenium complex ; Iron complexes ; Ruthenium complex ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Addition of Hydrofulleride [C60H]- to Coordinated, Unsaturated Hydrocarbons: Binding of Fullerene to Metal Complexes through Hydrocarbon BridgesHerrn Professor Herbert Walter Roesky zum 60. Geburtstag gewidmet.Hydrofulleride [C60H]- is added to the hydrocarbon ligands of the cationic complexes [(OC)5Re(η2-C2H4)]+, [(OC)3Mn-(η6-C6H6)]+, [(OC)3M(η5-C6H7)]+ (M = Fe, Ru), [(OC)3Fe(η5-C7H9)]+, and [(η5-C5H5)Fe(η6-C5H4CH2)]+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281017
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Controlled Conversion of the Transient 2-Mesityl-1,1-bis(trimethylsilyl)silene into a Tetrahydro-2,3-disilanaphthalene, a 1,2-Disilacyclobutane, or a 1,3-Disilacyclobutane (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1083-1088 
    Details
    ISSN: 0009-2940
    Keywords: Silenes ; Silene dimerization ; 1,2-Disilacyclobutanes ; 1,3-Disilacyclobutanes ; 2,3-Disilanaphthalene, tetrahydro- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mesityl[tris(trimethylsilyl)silyl]methanol (1) reacts with strong bases with elimination of trimethylsilanolate according to a Peterson-type mechanism, the outcome of the reaction being dependent on solvent, temperature, and nature of the organometallic base applied. Thus, 1 was converted by treatment with MeLi in ether at -78°C to (E)-1,2,3,8a-tetra -hydro-1-mesityl-5,7,8a-trimethyl-2,2,3,3-tetrakis (trimethylsi-lyl)-2,3-disilanaphthalene (3), formally a [2 + 4] cyclodimer of the transient silene (Me3Si)2Si=CHMes (2). The reaction of 1 with PhMgBr in THF after some days resulted in the formation of (Z)-3,4-dimesityl-1,1,2,2-tetrakis(trimethylsilyl) -1,2-disilacyclobutane (6) as the main product besides small quantities of 3, the polysilane (Me3SiSi(SiMe3)2CH2Mes (10), and the alkoxysilane (Me3Si)3SiCH(Mes)OSi(Si-Me3)2CH2Mes (7). Compound 6, the formal [2 + 2] cycloadduct of 2, can also be obtained by thermal treatment of 3 and is considered to be the thermodynamically more stable silene dimer whereas 3 is the kinetically preferred product. At high LiBr concentrations in the reaction mixture 1 was converted by PhMgBr in THF to (E)-2,4-dimesityl-1,1,3,3-tetrakis(tri- methylsilyl)-1,3-disilacyclobutane (13) besides 6 and [bis(tri-methylsilyl)silyl]mesityl(trimethylsiloxy)methane (11). The unforeseen formation of 13 is discussed as proceeding via the silene-lithium bromide adduct (Me3Si)2Si(Br)CH(Li)Mes (12). In the absence of LiBr 1 was converted by MeLi in THF at -78°C to 11 and the trisilane (Me3Si)2Si(Me)CH2Mes (4b). Probable pathways of the formation of all new compounds are discussed. For 6 and 13 the results of the X-ray structural analyses are given.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Metallkomplexe mit biologisch wichtigen Lisganden, LXXXLXXIX. Mitteilung: Lit.. (η3:η3-C10H16)Ru(IV)-Komplexe mit α-Aminocarboxylaten, α-Aminosäureestern und Peptidestern als Liganden (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1117-1125 
    Details
    ISSN: 0009-2940
    Keywords: 1,7-Dimethylocta-2,6-diene-1,8-diyl ; Ruthenium complexes ; α-Amino carboxylates ; α-Amino acid esters ; Peptide esters ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metal Complexes Containing Biologically Important Ligands, LXXXLXXIX. Mitteilung: Lit. .  -  (η3:η3-C10H16)Ru(IV) Complexes with α-Amino Carboxylates, α-Amino Acid Esters, and Peptide Esters as LigandsReactions of the chloro-bridged bis(allyl) complex [(η3:η3-C10H16)Ru(Cl)(μ-Cl)]2 with α-amino carboxylates and α-amino acid esters afford the complexes (η3:η3-C10H16)(Cl)RuNH2CHRCO2 (2) and (η3:η3-C10H16)(Cl)2-RuNH2CHRCO2R′ (3). Abstraction of chloride from 3 by Ag+ gives the N,O-chelates [(η3:η3-C10H16)(Cl)RuNH2CHRCO2R′]+BF4 (4). Cysteine methyl ester forms the N,S-chelate complex (η3:η3-C10H16)(Cl)RuNH2CH(CO2CH3)CH2S (5), and with histidine methyl ester a dinuclear complex 6 with N,N-histidine bridge is obtained. Compound 3d with L-PheOEt as ligand was characterized by X-ray diffraction.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    [MeO(CH2CH2O)3(CH2)3C5Me4]FeCl: A Halfsandwich Iron (II) Chloride Complex of Remarkable Stability (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1135-1136 
    Details
    ISSN: 0009-2940
    Keywords: Hemilabile ligands ; Cyclopentadienyl ligands, functionalised ; Iron compounds ; Halfsandwich complex ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of iron(II) chloride with one equivalent of [MeO-(CH2CH2O)3(CH2)3C5Me4]Li in THF yields the title halfsand-wich complex 1, which is stable in solution up to room temperature. Compound 1 reacts with C5H5Li and CO to give [MeO(CH2CH2O)3(CH2)3C5Me4]Fe(C5H5) (2) and [MeO-(CH2CH2O)3(CH2)3C5Me4]Fe(CO)2CI (3), respectively, in high yields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    [Cp4Fe4(E2)2] Clusters with Triangulated Dodecahedral Fe4E4 Skeletons (E = P, As)Dedicated to Professor Herbert Schumann on the occasion of his 60th birthday. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1145-1148 
    Details
    ISSN: 0009-2940
    Keywords: P2, As2, P2S2, and P2Se2 ligands ; Iron complexes ; Triangulated dodecahedra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermolysis of [CpFe(CO)2]2 (1) and P4 or As4 affords the iron clusters [Cp4Fe4(E2)2], E = As (2a), P (2b), the Fe4E4 skeleton of which consists of a triangulated dodecahedron. S8 and gray Se oxidize the P2 ligands of 2b with formation of [Cp4Fe4(P2X2)2], X = S (3a), Se (3b), complexes with the hitherto unknown P2X2 ligands, 2a, b and 3a, b have been characterized by X-ray crystallography.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Functionalized Diorganozinc Compounds: Key Reagents for the Synthesis of Enantiomerically Pure 2,5-Disubstituted cis- and trans-Tetrahydrofurans (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1021-1028 
    Details
    ISSN: 0009-2940
    Keywords: Synthesis, stereoselective ; Catalysis ; Tetrahydrofurans ; Dialkylzinc reagents ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,4-Diol derivatives 4a-i were synthesized stereoselectively by either reagent- or catalyst-controlled routes using the addition of functionalized diorganozinc reagents to aldehydes. The stereoselectivities along the reagent-controlled synthetic path were in the range between 80:20 and 95:5. The stereoselectivities along the catalyst route exceeded 95:5. The 1,4-diol derivatives 4 thus obtained were transformed into enantiomerically pure cis- and trans-2,5-disubstituted tetrahydrofurans (16-20) by means of an intramolecular Williamson reaction.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281010
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Contributions to the Chemistry of Boron, 231Part 230: Ref.. Synthesis and Structures of Borylated HydrazinesDedicated to Professor H. P. Fritz on the occasion of his 65th birthday. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1187-1194 
    Details
    ISSN: 0009-2940
    Keywords: Hydrazines ; N,N'-bis(diphenylboryl)-N,N'-dimethyl- ; N,N'-bis(diphenylboryl)-N',N'-dimethyl- ; N,N'-bis(dimethylphenylsilyl)- ; N,N'-bis(chloromesitylboryl)-N'-phenyl-N'-(trimethylsilyl)- ; 1,2,4,5,3,6-Tetrazadiborinane, 1,2,4,5-tetrakis(tert-butyldimethylsilyl)-3,6-difluoro- ; Triazadiborolidine, dihydro-, derivative ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The diboration of the diazene PhN = NSiMe3 (15) by diborane(4) derivatives provides a new synthetic route to N,N'-diborylated hydrazines. The product formed depends on the type of the diborane(4) compound. Thus, addition of dimesityldiboron dichloride to 15 in a 1:1 ratio afforded (mesCIB)PhN-N(SiMe3)(BClmes) (16) while bis(dimethyl-amino)diboron dichloride was found to react in a 1:2 ratio to give a triazadiborolidine derivative 17. In addition, it was demonstrated that in the solid state Me2N-N(BPh2)2 (8) is a derivative of a three-membered dihydroazadiboriridine C while its isomer, (Ph2B)MeN-NMe(BPh2) (7), forms no BN coordinative bond. The new 3,6-difluoro-1,2,4,5-tetraza-3,6-diborine 13 shows a twist conformation. The molecular structures of all these compounds were determined by X-ray crystal structure analysis, and the influence of the B substituent on the conformation is discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Metal Complexes of Functional Isocyanides, XXV. Amino(hydrazino)carbene Complexes (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1061-1068 
    Details
    ISSN: 0009-2940
    Keywords: N-Isocyanides ; N-Isocyanodialkylamine complexes ; Carbene complexes ; Imaging-Plate data collection ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The N-isocyanodialkylamine metal complexes [M(CO)5CN-NR2] (M = Cr, W), trans-[MI2(CNNR2)2] (M = Pd, Pt), trans-[Pt(Cl)(CNNR2)(PPh3)2]BF4, and cis-[PtCl2(CNNR2)(PPh3)] [R = Et, iPr; 2 R = -{CHMe(CH2)3CHMe}-] react with primary amines to give the amino(hydrazino)carbene metal complexes [M(CO)5(C(NHR′)NHNR2}] (R′ = Me, nPr, Cy) (1-9), trans-[PtI2{C(NHMe)NHNR2}2] (10-12) and trans, and the amine adducts cis-[PtCl2{C(NHMe)NHNC(H)(Me) (CH2)3CHMe}(PPh3)] H2NMe (14), and trans-[PdI2{C (NHMe)NHNC(H)(Me)(CH2)3CHMe}2] 2 H2NMe (15). With secondary amines the amino(hydrazino)carbene metal complexes trans (18) and trans-[PtCl{C(NEt2)NHNEt2} (PPh3)2]BF4 (19) Were isolated. The complexes trans-[PtI2{C(NHCy)NHNiPr2}CNNiPr 2] (20) and trans-[PdI2 (NH2Cy){C(NHCy)NHNiPr2}] (21) were obtained by reaction of trans-[MI2(CNNiPr2)2] (M = Pd, Pt) with cyclohexylamine. The structures were assigned on the basis of IR, NMR- (1H, 13C, 31P), and mass spectroscopy as well as an X-ray structural analysis of 21.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Metallocenophanes, VIIPart VI: Ref.. Preparation and Characterisation of the Disilver(I) Complexes of Conjugated Polyenes with [2.2.2]Paracyclophanyl End Groups (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1079-1082 
    Details
    ISSN: 0009-2940
    Keywords: [2.2.2]Paracyclophanes ; Polyenes ; Silver complexes ; X-Ray structural analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of the disilver(I) complexes 3 and 4, polyene metal complexes that are terminally substituted with [2.2.2]paracyclophanyl units, is described. NMR spectro-scopic studies on the disilver perchlorate complex 3b showed that (a) the sites of complexation are the cyclophane groups and (b) the olefinic spacers do not overly perturb the overall complexation properties of the individual [2.2.2]paracyclo-phanyl groups. The crystal structures of the disilver hexafluo-roantimonate complexes 4a-b were determined. The use of the hexafluoroantimonate counterion and solvent mixtures containing toluene both proved crucial in obtaining single crystals; toluene is incorportated into the crystal lattices.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Highly Substituted Tris(pyrazolyl)methane Ligands and Some Zinc Complexes Thereof (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1095-1103 
    Details
    ISSN: 0009-2940
    Keywords: Zinc complexes ; Tridentate ligands ; Tris(pyrazolyl)methane ; Reactivity ; Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tris(pyrazolyl)methane ligands in which two or three of the pyrazole carbon atoms bear organic substituents (L1-L7) were synthesized from chloroform and the corresponding pyrazole under phase transfer conditions. Their behavior towards zinc salts was found to span the range from no reaction at all to hydrolytic destruction. One hydrolysis product isolated and structurally characterized was the perchlorate complex [(HPz5)3Zn-OClO3]ClO4 (1), other ones were the 2:1 complexes (HPz3)2ZnBr2 (2) and (HPz6)2Zn(NO3)2 (3, HPzn = substituted pyrazole). Zinc perchlorate and tris(trimethylpy-razolyl)methane (L2) formed the octahedral binary complex [L22Zn](ClO4)2 (4) as evidenced by a structure determination. Zinc halides produced the 1:1 complexes L1 · ZnBr2 (5), L4 · ZnCl2 (6), and L4 · ZnBr2 (7), which according to the structure determinations of 6 and 7 contain tetrahedral ZnN2Hal2 units with only bidentate tris(pyrazolyl)methane ligands. In contrast, the zinc nitrate complex L4 · Zn(NO3)2 (8) was found to have an octahedral structure with mono- and bidentate nitrate and tridentate L4. The bromide complex 7 was converted by silver perchlorate hydrate into the labile compound [L4 · ZnBr]ClO4 (9) and then into the unstable product [L4 · Zn-OH2](ClO4)2 (10), both presumed to contain zinc in a tetrahedral ZnN3Br or ZnN3O environment, respectively. The ease of hydrolytic self-destruction prevented the exploitation of the reactivity of 9 and 10 in analogy to that of the corresponding tris(pyrazolyl)borate zinc complexes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Unusual Complexation Behavior of Metallomacrocycles Based on Isothiosemicarbazides with Respect to Alkali and Alkaline Earth Metal Ions: Novel 2:1 Associates (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1089-1093 
    Details
    ISSN: 0009-2940
    Keywords: Metallomacrocycles ; Nickel complexes ; Complexation reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions between alkali and alkaline earth metal ions and nickel(II) macrocycles based on S-alkylated isothiosemi-carbazides with different crown ether cavity size were studied in propylene carbonate by spectrophotometric and calorimetric titrations. Metallomacrocycles 1 and 2 exhibit normal behavior on 1:1 complexation with alkali- and alkaline earth metal ions and resemble in this respect 15C5 and 18C6, respectively. The most stable complexes are formed by these “ligands” when the diameter of the cation and the crown ether hole have approximately the same size. The most striking feature of the complexation processes studied is the formation of 1:2 metal-ligand associates even in the case of the smallest cations. These associates are very different from “normal” crown ether sandwich complexes. In reality, the particle formed is an associate between a 1:1 complex, in which the corresponding metal ion is well accommdated inside the ligand cavity, and a second metallomacrocyclic ligand. Their formation is disfavored by enthalpic contributions. A special kind of “switch” from these associates to normal sandwich complexes takes place in the case of 1, when the cation diameter compared to hole size increases. The macrocycle 2 forms this kind of associates with all akali and alkaline earth ions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Synthesis and Reactivity of Silicon Transition Metal Complexes, 3433. Mitteilung: Lit.. Pentachlordisilanyl- und Disilanyl-Komplexe von Molybdän und Wolfram: Darstellung, Struktur und spektroskopische CharakterisierungHerrn Professor Hubert Schmidbaur zum 60. Geburtstag gewidmet. (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1109-1115 
    Details
    ISSN: 0009-2940
    Keywords: Silicon transition metal complexes ; Metallodisilanes ; Nucleophilic metallation ; Cl/H exchange at silicon ; Raman spectroscopy ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Reactivity of Silicon Transition Metal Complexes, 34[*].  -  Pentachlorodisilanyl and Disilanyl Complexes of Molybdenum and Tungsten: Synthesis, Structure, and Spectroscopic CharacterizationReaction of the lithium metallates Li[M(PMe3)(CO)2C5R5] [M = Mo, W; R = H (1a, b), Me (1c, d)] with Si2Cl6 (2) leads to the formation of the pentachloro(metallo)disilanes 5R5(OC)2(Me3P)M - SiCl2 - SiCl3 (3a - d), which are transformed into the metallo disilanes C5R5(OC)2(Me3P)M - SiH2 - SiH3 (4a - d) on treatment with LiAlH4. The disilanes 4a - d are reconverted into 3a - d in the presence of tetrachloromethane. Extensive spectroscopic investigations (NMR, Raman, and IR spectroscopy) were performed to establish the transition-metal effect especially with respect to the H5Si2 ligand. The molecular structure of C5Me5(OC)2(Me3P)W - SiCl2 - SiCl3 (3d) was determined by single-crystal X-ray diffraction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Octacarbonylbis {μ-(tris(trimethylsilyl)methyl]indany l} dimanganese with Two Monoalkyl Indium Groups Bridging the Mn-Mn Bond (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1137-1139 
    Details
    ISSN: 0009-2940
    Keywords: Tetraindane(4) ; Indium(I) ; Mn-Mn bond ; Indium alkyl bridge ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetrahedra-tetrakis[tris(trimethylsilyl)methyl]tetraindane(4) (1) reacts with decacarbonyldimanganese(0) to yield the bright red crystalline title compound 2, in which two carbonyl ligands are replaced by two InR fragments. The crystal structure determination of 2 shows two Mn(CO)4 groups (Mn-Mn 313.7 pm) bridged by two monoalkylindium units and a planar Mn2In2 molecular center.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Thioselonocarboxylic Ester, Selenetane, and Dihydrodiselenine Complexes Prepared from Pentacarbonyl(selenobenzaldehyde)tungsten with π-Donor-Substituted Alkynes (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1149-1156 
    Details
    ISSN: 0009-2940
    Keywords: Selenoaldehyde complex ; Thioselonocarboxylic ester complexes ; Selenetane complex ; Dihydrodiselenine complex ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pentacarbonyltungsten-coordinated selenobenzaldehyde, [(CO)5W{Se=C(Ph)H}] (1), reacts with tBu-C≡C-SMe (2) by insertion of the C≡C into the Se=C bond to form in a highly regio- and stereoselective manner the α,β-unsaturated thioselonocarboxylic ester complex (Z)(C=C)-[(CO)5W{≡1-Se=C(SMe)C(tBu)=C(Ph)H}] (3). The thioselonocarboxylic ester ligand is cleaved intact from the metal by treatment of 3 with [NEt4]Br. Three complexes are formed in the reaction of 1 with Me-C≡C-SMe (5): the thioselonocarboxylic ester complex [(CO)5W{≡1-Se=C(SMe)C(Me)=C(Ph)H}] (6) as a mixture of the (E) and (Z)(C=C) isomers, a selenetane complex (7) and a dihydrodiselenine complex (8). The product distribution depends on the ratio 1:5 and on the solvent. The reaction of 1 with the bis(organylthio)alkynes RS-C≡C-SR (9) [R = Me (a), iPr (b), 2,6-C6H3Me2 (c)] yields mixtures of the (E) and (Z)(C=C) isomers of the α,β-unsaturated α-organylthio thioselonocarboxylic ester complexes [(CO)5W{≡1-Se=C(SR)C(SR)=C(Ph)H)] (10a-c). In contrast, the reaction of 1 with tert-butoxyethyne, H-C≡C-OtBu (11), affords a bis(pentacarbonyltungsten) 5,6-dihydro-1,2-diselenine complex (12). Compound 12 is probably formed by consecutive reaction of 1 with 11 to give the selonocarboxylic ester complex [(CO)5W{≡1-Se=C(OtBu)C(H)=C(Ph)H}] which then further reacts as a heterodiene by highly regioselective [4 + 2] cycloaddition with the Se=C bond of a second molecule of 1 to give 12. In the reaction of 1 with 5 and 9a the isomer with a trans arrangement of C(=Se)SMe and Ph is the kinetically controlled reaction product [(E)-6 and (Z)-10a, respectively]. The formation of (E)-6 and (Z)-10a is followed by isomerization until an (E)/(Z) equilibrium is reached. Complexes 3 and 7 were characterized by X-ray structural analyses.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281203
    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...