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  • 1
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 159. [2 + 2]-Cycloadditionen von (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)boran mit Kohlenstoffdichalkogeniden (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3748-3758 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 159. [2 + 2] Cycloadditions of (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)borane with Carbon Dichalcogenides[2 + 2] Cycloadditions of CO2, COS, CS2, and CSe2 and the aminoiminoborane 1 give access to the azaboretidines 2-5. These decompose thermally or photolytically with formation of (CH3)3C—N =C =E′ (E′ = O, S, Se) and the dimers of the (tetramethylpiperidino)boron chalcogenides 7-9. The X-ray structure analyses of the sulfur containing heterocycles 4 and 8 reveal the presence of planar four-membered rings. The C2N-unit of the tetramethylpiperidino group in 4 approaches a perpendicular arrangement with four-membered ring (interplanar angle 72°), in 8 however, the two planes are twisted to each other by 17° only.
    Notes: CO2, COS, CS2 und CSe2 reagieren mit dem Aminoiminoboran 1 unter [2 + 2]-Cycloaddition zu den Azaboretidinen 2-5. Diese zerfallen thermisch oder photolytisch unter Abspaltung von (CH3)3C—N =C =E′ (E′ = O, S, Se) und Bildung der dimeren (Tetramethyl-piperidino)borchalkogenide 7-9. Die Röntgenstrukturanalyse der schwefelhaltigen Heterocyclen 4 und 8 zeigt planare Vierringe auf. In 4 bildet das C2N-Strukturelement der Tetramethylpiperidino-Gruppe mit der Vierring-Ebene einen Winkel von 72°, in 8 sind die beiden Ebenen dagegen nur um 17° verdrillt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180927
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  • 2
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 161. Reaktionen protonenaktiver Verbindungen mit (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)boran (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3759-3770 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 161. Reactions of Protic Reagents with (tert-Butylimino)(2,2,6,6-tetramethylpiperidino)boraneThe aminoiminoborane 2 adds protic reagents of type HX (X = OH, OR, OCOR, SH, SR, NH2, NHR, NHNR2) across the formal BN triple bond regiospecifically forming (tert-butylamino)(2,2,6,6-tetramethylpiperidino)boranes (3-7, 12, 13, 15, 16a,b, 17-27) which are inert towards ligand redistribution. The relative rates of addition are primarily governed by steric factors (NH3 〉 NH2R 〉 HNR2; HOR 〉 HSR 〉 HNR2). Bulky amines HNR2 will not add to 2. Excess HX (X = OH, OR, OC(O)R) reacts with the boranes formed on 1:1 addition by breaking BN bonds; however, no prediction can be made concerning which BN bond in tmp[(CH3)3CNH]BX will be cleaved.
    Notes: Das Aminoiminoboran 2 addiert protonenaktive Verbindungen HX (X = OH, OR, OCOR, SH, SR, NH2, NHR, NHNR2) regiospezifisch an die formale BN-Dreifachbindung. Dabei entstehen gegen Substituentenaustausch inerte (tert-Butylamino)(2,2,6,6-tetramethylpiperidino)borane (3 - 7, 12, 13, 15, 16a,b, 17 - 27). Die Anlagerungsgeschwindigkeit hängt qualitativ von sterischen Faktoren ab (NH3 〉 NH2R 〉 HNR2; HOR 〉 HSR 〉 HNR2). Bei sterischer Überfrachtung unterbleibt die Anlagerung an 2. Bei HX-Überschuß (X = OH, OR, OC(O)R) reagieren die durch 1:1-Addition entstandenen Borane unter Spaltung von BN-Bindungen, jedoch ist nicht vorhersehbar, welche der beiden BN-Bindungen in tmp[(CH3)3CNH]BX dabei gelöst wird.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180928
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  • 3
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 146. Über die Reaktion von Tetrazadiborinanen mit Heterokumulenen: Pseudodipolare [2 + 3]-Cycloadditionen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 483-494 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 146 Reactions of Tetrazadiborinanes with Heterocumulenes: Pseudodipolar [2 + 3]-CycloadditionsCO2, COS, and CS2 scavenge the 1,3-dipolar unit \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R'}\mathop {{\rm B - }}\limits^ \oplus {\rm NR - }\mathop {\rm N}\limits^{\rm \Theta } {\rm R} $\end{document} from the tetrazadiborinanes 3. [2 + 3]-Cycloadducts are formed in a pseudodipolar reaction, namely oxadiaza- and thiadiazaborolidines of type 7, 8 and 4. A reaction mechanism is suggested.  -  The thiadiazaborolidine 4b contains a planar five-membered ring according to an X-ray structure determination. Short BN, NN, and CN bond distances suggest a heteroaromatic ring system. High polarity is associated with the thioxo group. In contrast, the oxadiazaborolidinones 8a, b are in an equilibrium with their dimers in solution.
    Notes: CO2, COS und CS2 fangen aus den Tetrazadiborinanen 3e) den 1,3-Dipol \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R'}\mathop {{\rm B - }}\limits^ \oplus {\rm NR - }\mathop {\rm N}\limits^{\rm \Theta } {\rm R} $\end{document} ab. In einer pseudodipolaren Reaktion bilden sich als [2 + 3]-Cycloaddukte die Oxadiaza- und Thiadiazaborolidine 7, 8 und 4. Ein Reaktionsmechanismus wird diskutiert.  -  Nach Röntgenstrukturanalyse enthält 4b einen planaren Fünfring. Kurze BN-, NN- und CN-Abstände legen ein heteroaromatisches System nahe, wobei der Thioxo-Gruppe eine erhebliche Polarität zuzuweisen ist. Die Oxadiazaborolidinone 8a, b stehen in Lösung im Gleichgewicht mit ihrem Dimeren.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180210
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  • 4
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 162. Zur Reaktion von Chlorwasserstoff mit (tert-Butylimino)-(tetramethylpiperidino)boran und seinem Diazadiboretidin-Dimeren (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 4716-4724 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 162. The Reaction of Hydrogen Chloride with (tert-Butylimino)(tetramethylpiperidino)borane and its Diazadiboretidine DimerHydrogen chloride adds to the amino-imino-borane 1 to give tmpB(Cl)NHC(CH3)3 (3) (tmp = 2,2,6,6-tetramethylpiperidino group), which is also the first product to be isolated in the reaction of HCl with [tmp-B = NC(CH3)3]2 (2). Further interaction leads to the salt tmpHBC[NH-C(CH3)3]Cl (7c), which reacts with HCl to finally yield [tmpH2]Cl. Aminolysis of tmpBCl2 (9) with tert-butylamine produces no diazadiboretidine 2 but 3 and tmpB[NHC(CH3)3]2 (10). - The X-ray structure analysis of 2 (monoclinic, P21/n, Z = 2) reveals a point group symmetry Ci for this molecule. Its planar B2N2 four-membered ring has the shape of a slightly diamond distorted square. The tmp groups are almost orthogonally oriented towards the B2N2 ring. All BN bond lengths are equal (BN 146.7 pm).
    Notes: Chlorwasserstoff addiert sich an das Amino-imino-boran 1 zu tmpB(Cl)NHC(CH3)3 (3) (tmp = 2,2,6,6-Tetramethylpiperidino-Gruppe), das auch das erste faßbare Produkt der Einwirkung von HCl auf [tmp-B=NC(CH3)3]2 (2) ist. Die weitere Umsetzung führt zum Salz tmpHBC[NH-C(CH3)3]Cl (7c), das mit HCl letztlich zu [tmpH2]Cl weiterreagiert. Die Aminolyse von tmpBCl2 (9) mit tert-Butylamin liefert kein Diazadiboretidin 2, sondern 3 und tmpB[NHC(CH3)3]2 (10). - Nach der Röntgenstrukturanalyse besitzt 2 (monoklin, P21/n, Z = 2) die Symmetrie der Punktgruppe Ci. Der planare B2N2-Vierring ist schwach rautenförmig gebaut. Die tmp-Gruppe steht fast orthogonal zum Vierring. Alle BN-Abstände sind gleich lang (BN 146.7 pm).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851181207
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  • 5
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    Electronic Resource
    Beiträge zur Chemie des Bors, 145. Synthese und Charakterisierung von Tris(dihalogenboryl)aminen (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 86-96 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 145. Synthesis and Characterisation of Tris(dihaloboryl)aminesTris(dichloroboryl)amine (1) results from stannazane cleavage of N(SnMe3)3 with a large excess of BCl3. Transhalogenation of 1 with BBr3 leads to N(BBr2)3 (7) by Cl/Br exchange while antimony trifluoride provides access to N(BF2)3 (8) which is stable up to ∽ 100°C. NMR data and mass spectral fragmentation are discussed. The former suggests a planar geometry for N(BF2)3 (8) while the latter indicates a high stability of the iminoborane X2B—N = BX in the gas phase.
    Notes: Tris(dichlorboryl)amin (1) entsteht bei der Stannazanspaltung von N(SnMe3)3 mit einem großen BCl3-Überschuß. Transhalogenierung von 1 mit BBr3 liefert unter Cl/Br-Austausch N(BBr2)3 (7), während es von Antimontrifluorid in N(BF2)3 (8) übergeführt wird, das nur bis ∽ 100°C stabil ist. Kernresonanzspektroskopische Daten und die massenspektrometrische Fragmentierung werden diskutiert. Erstere legen eine planare Molekülgeometrie für N(BF2)3 (8) nahe, letztere deuten auf eine relativ hohe Stabilität der Iminoborane X2B—N = BX in der Gasphase hin.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180109
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  • 6
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 154. Addition von Trimethylsily-Verbindungen und von anderen Elektrophilen an (tert-Butylimino) (tetramethylpiperidino)boran (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2144-2146 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 154. Addition of Trimethylsilyl Compounds and Some Other Electrophiles to (tert-Butylimino)-(tetramethylpiperidino)boraneThe amino-imino borane 3 adds methyl triflate and triflic acid to form tricoordinated borane derivatives (1, 4). In contrast, trimethylsilyl triflate and trimethylsilyl iodide yield salts (2, 5) of the [tert-butyl(trimethylsiyl)amino](tetramethylpiperidino)boron(1+) cation containing a dicoordinated boron atom.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180536
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  • 7
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 173. Über Salze des Bis(diisopropylamino)bor(1+)-Kations (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2075-2079 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 173. Salts of the Bis(diisopropylamino)boron(1+) CationBromobis(diisopropylamino)borane (1) reacts with aluminium and gallium tribromide to produce stable salts of type [(iPr2N)2B]EBr4 (2, 3). Silver triflate converts 1 into bis(diisopropylamino)[(trifluoromethyl)sulfonyloxy]borane (4), while silver tetratriflatoborate produces a mixture of 4 with the salt [(iPr2N)2B]B(OSO2CF3)4 (6). Furthermore (diisopropylamino)bis[(trifluoromethyl)sulfonyloxy]borane (7) is formed.
    Notes: Bis(diisopropylamino)borbromid (1) reagiert mit Aluminium-oder Galliumtribromid zu den stabilen Salzen [(iPr2N)2B]EBr4 (2, 3), während 1 mit Silber-triflat Bis(diisopropylamino)-[(trifluormethyl)sulfonyloxy]boran (4) liefert. Silber-tetratriflatoborat setzt sich mit 1 zu einem Gemisch von 4 mit dem Salz [(iPr2N)2B]B(OSO2CF3)4 (6) um. Ferner entsteht (Diisopropylamino)bis[(trifluormethyl)sulfonyloxy]boran (7).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190702
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  • 8
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 182 Versuche zur Darstellung von Methylenboranen: Untersuchungen zur Dehydrohalogenierung sterisch anspruchsvoller Amino-organylborhalogenide (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 345-350 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: LiCMe3 reacts with tmpB(Hal)CHMe2 with substitution to give tmpB(CMe3)CHMe2 (tmp=2,2,6,6-tetramethylpiperidino) but not by dehydrohalogenation. In the presence of Me2NCH2-CH2NMe2 the aminoborane tmpB(NMe2)CHMe2 is also formed. Using Litmp in toluene the benzyl- and tolyboranes tmpB(R)CHMe2 are obtained. The (diphenylmethyl)boranes tmpB(Hal)CHPh2 react with Na(HBEt3) to produce tmpB(H)CHPh2, and substitution is also achieved with LiCMe3. While the 9-fluorenylboron fluoride tmpB(F)C13H9 is converted into tmpB(H)C13H9 by Na(HBEt3) the deep red tmpB(CMe3)C13H8Li (15) is formed in a 1:2 reaction with LiCMe3. 15 was characterized by its reaction products 13, 14 formed with HCl and CH3I, respectively. The formation of 15 is explained by a methyleneborane intermediate 2, resulting from dehydrofluorination of 11.
    Notes: Anstelle einer Dehydrohalogenierung erfolgt bei der Einwirkung von LiCMe3 auf tmpB(Hal)CHMe2 eine Substitution zu tmpB(CMe3)CHMe2 (tmp=2,2,6,6-Tetramethylpiperidino); in Gegenwart von Me2NCH2CH2NMe2 wird auch tmpB(NMe2)CHMe2 erhalten. Litmp in Toluol reagiert mit 3 zum Benzyl- bzw. Tolylboran tmpB(R)CHMe2. Die (Diphenylmethyl)borane tmpB(Hal)-CHPh2 setzen sich mit Na(HBEt3) zum Hydridoboran tmp B(H)CHPh2 um; mit LiCMe3 erfolgt ebenfalls Substitution. Das 9-Fluorenylborfluorid tmpB(F)C13H9 (11) wird von Na(HBEt3) nicht dehydrohalogeniert; man erhält das Hydrid 12. Mit LiCMe3 entsteht tiefrotes tmpB(CMe3)C13H8Li (15), das in die Derivate tmpB(CMe3)C13H9 (13) bzw. tmpB(CMe3)C13H8Me (14) überführbar ist. Die Bildung der Lithium-Verbindung wird über eine Methylenboran-Zwischenstufe 2 erklärt, die durch Dehydrofluorierung von 11 entsteht.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19871200316
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  • 9
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    Electronic Resource
    Beiträge zur Chemie des Bors, 158. Addukte von Aluminium- und Galliumhalogeniden an ein Aminoiminoboran (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2554-2556 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 158. Addition Compounds of Aluminium and Gallium Halides with an Amino Imino Borane(tert-Butylimino)(2,2,6,6-tetramethylpiperidino)borane (4) adds AlCl3, AlBr3, or GaCl3 at the tert-bytylimino group generating adducts 5a - c which retain the dicoordinated boron atom.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180631
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  • 10
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    Beiträge zur Chemie des Bors, 155. N-Borylierte Borazine (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3020-3031 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 155. N-Borylated BorazinesDouble stannazane cleavage of (CH3)2B-N[Sn(CH3)3]2 (1) by CH3BBr2 (1:1) yields [(CH3)2B-N=BCH3]3 (4a). In analogy, N[Sn(CH3)3]3 (2) reacts with 2 mols of CH3BBr2and BCl3 to give the N,N′N″-borylated borazines [(CH3)BrB-N=BCH3]3 (4b) and [Cl2B-N=BCl]3 (4c), respectively. The latter on transhalogenation by BBr3 gives access to [Br2B-N=BBr]3 (4d). - NMR and IR spectra of 4a-i are in accord with the presence of boryl groups oriented orthogonally or strongly twisted to the borazine ring. Mass spectroscopic fragmentation patterns are characterized by the formation of radicals (CH3Br) as well as by the elimination of BX3 (or RBX2), borylated iminoboranes, and finally diazadiboretidines.
    Notes: Doppelte Stannazanspaltung von (CH3)2B-N[Sn(CH3)3]2 (1) mit CH3BBr2 (1:1) führt zu [(CH3)2B-N=BCH3]3 (4a). Analog dazu erhält man aus N[Sn(CH3)3]3 (2) mit 2 mol CH3BBr2 bzw. BCl3 die N,N′,N″-borylierten Borazine [(CH3)BrB-N=BCH3]3 (4b) und [Cl2B-N=BCl]3 (4c). Letzteres liefert bei der Umhalogenierung mit Bortribromid [Br2B-N=BBr]3 (4d). - Aus den NMR- und IR-Spektren erkennt man, daß die Borylgruppen in 4a-i orthogonal oder sehr stark verdrillt zur Borazin-Ringebene stehen. Die-massenspektrometrische Fragmentierung erfolgt sowohl unter Abspaltung eines Radikals (CH3, Br), als auch unter Eliminierung von BX3 (bzw. RBX2), borylierten Iminoboranen bzw. Diazadiboretidinen.
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    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180803
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