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  • 1
    Electronic Resource
    Electronic Resource
    1,3-Dipolare Cycloadditionen, 82. Kinetik und Mechanismus der Cycloadditionen des C-(2,2′-Biphenylylen)-Nα-(4-chlorphenyl)-Nβ-cyan-azomethinimins (1977)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 578-595 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Dipolar Cycloadditions, 82. Kinetics and Mechanism of the Cycloadditions of C-(2,2′-Biphenylylen)-Nα-(4-chlorphenyl)-Nβ-cyan-azomethinimine ImineThe cycloaddition rates of the title compound to 22 dipolarophiles in chlorobenzene was measured photometrically; the k2 values range over more than 4 powers of ten. Conjugation as well as electron-attracting and -releasing substitution in the ethylenic dipolarophile increase the activity. The azomethine imine 1 belongs to those 1,3-dipoles for which both HOMO-LUMO interactions with the dipolarophile influence the energy of the transition state to a comparable extent. The activity scale of dipolarophiles is compared with those which were measured versus N-methyl-C-phenylnitrone, diphenylnitrilimine and benzonitrile oxide. 1,3-Dipoles of the allyl type, in contrast to the ones of the propargyl-allenyl type, react especially fast with acetylenic carboxylic esters. - The activation entropies of the cycloadditions of 1 amount to -29 to -35 e. u. - With increasing solvent polarity the k2 values of the reaction of 1 with dimethyl acetylenedicarboxylate is reduced 6 fold. The dipole moments of reactants and adduct suggest a decrease of charge separation in the activation process of the concerted cycloaddition.
    Notes: Die Geschwindigkeit der Cycloadditionen der Titelverbindung an 22 Dipolarophile wurde in Chlorbenzol photometrisch gemessen; die k2-Werte überstreichen mehr als 4 Zehnerpotenzen. Konjugation sowie elektronen-anziehende oder -liefernde Substitution im ethylenischen Dipolarophil erhöhen die Aktivität. Das Azomethin-imin 1 gehört zu den 1,3-Dipolen, bei denen beide HOMO-LUMO-Wechselwirkungen in gleicher Größenordnung die Energie des Übergangszustandes der Cycloaddition beeinflussen. Die Aktivitätsskala der Dipolarophile wird mit denen, die gegenüber N-Methyl-C-phenylnitron, Diphenylnitrilimin und Benzonitriloxid gemessen wurden, verglichen. 1,3-Dipole vom Allyl-Typ reagieren im Gegensatz zu denen des Propargyl-Allenyl-Typs rascher mit Acetylencarbonestern als mit Ethylencarbonestern. - Aktivierungsentropien von -29 bis -35 Clausius wurden gemessen. - Mit steigender Solvenspolarität fällt der k2-Wert der Cycloaddition von 1 an Acetylendicarbonester um den Faktor 6; die Dipolmomente von Reaktanten und Addukt lassen eine Verminderung der Ladungstrennung im Aktivierungsvorgang der konzertierten Cycloaddition erwarten.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19771100219
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  • 2
    Electronic Resource
    Electronic Resource
    Zur Existenz eines Silaolefins: Synthese und Kristallstrukturen von Wittig- und Diels-Alder-Produkten in Reaktionen lithiierter fluorsilylfunktioneller Diazasilacyclopentene mit Benzaldehyd und Methacrolein (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 282-289 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Existence of a Silaolefin: Synthesis and Crystal Structures of Wittig and Diels-Alder Products in Reactions of Lithiated (Fluorosilyl)diazasilacyclopentenes with Benzaldehyde and MethacroleinLithium salts of 1,2-diaza-3-sila-5-cyclopentenes react with fluorosilanes and aminofluorosilanes to give 4-(fluorosilyl)-substituted compounds 1 - 4. By reaction with tert-butyllithium 1 - 4 themselves form lithium salts 5 - 8, which react with fluorosilanes in a second substitution giving 9 and 10.5 and 7 undergo a Wittig-type reaction with benzaldehyde to form the benzylidene derivative 11. Spirocyclic Diels-Alder adducts (12, 13) are obtained from the reaction of 5 and 6 with 2-methyl-2-propenal. The propenylidene derivative 14 is formed as a by product. With excess 2-methyl-2-propenal, 12 reacts as a dienophile giving the oligocyclic Diels-Alder adducts 15 and 16. The crystal structures of 11 and 15 are reported.
    Notes: Lithiumsalze der 1,2-Diaza-3-sila-5-cyclopentene reagieren mit Fluorsilanen und Aminofluorsilanen zu den 4-(Fluorsilyl)-substituierten Verbindungen 1 - 4. In Reaktion mit tert-Butyllithium bilden 1 - 4 erneut Lithiumsalze (5 - 8), die mit Fluorsilanen unter Zweitsubstitution zu 9 und 10 reagieren. In Wittig-analoger Reaktion reagieren 5 und 7 mit Benzaldehyd zum Benzyliden-Derivat 11. Spirocyclische Diels-Alder-Addukte (12, 13) werden aus 5 und 6 mit 2-Methyl-2-propenal erhalten. Als Nebenprodukt entsteht das Propenyliden-Derivat 14. Mit überschüssigem Dien (2-Methyl-2-propenal) reagiert 12 als Dienophil zu den oligocyclischen Diels-Alder-Addukten 15 und 16. Kristallstrukturen von 11 und 15 werden mitgeteilt.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160132
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  • 3
    Electronic Resource
    Electronic Resource
    Synthese cyclischer Silylhydrazine - Kristallstruktur eines fünfgliedrigen Kreuz-Dimeren (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 290-298 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Cyclic Silylhydrazines - Crystal Structure of a Five-membered Cross Dimerisation ProductN,N-Bis(fluorosilyl)amines (1 - 3) react with dilithiated hydrazines to give four- and five-membered silylhydrazine rings (4 - 8). The isomerisation of a 3-(tert-butylamino)-1,3-diaza-2,4-disilacyclobutane (8) to a 1,2,4-triaza-3,5-disilacyclopentane (9) has been demonstrated. Lithium salts of silylhydrazines react with fluorosilanes to give substitution products (10 - 15). Dilithiated hydrazine reacts with Me2SiF2 yielding N(SiFMe2)3 (16). The formation of isomeric N-(fluorosilyl)-N,N′-bis(trimethylsilyl)- and N′-(fluorosilyl)-N,N-bis(trimethylsilyl)hydrazines has been accomplished via ring-closure reactions (17 - 19) and confirmed by the crystal structure determination of a five-membered ring cross dimer (19). The ten-membered bicyclic ring system (22) is obtained by the reaction of (14) with dilithiated hydrazine.
    Notes: N,N-Bis(fluorsilyl)amine (1 - 3) reagieren mit dilithiierten Hydrazinen zu vier- und fünfgliedrigen Silylhydrazinringen (4 - 8). Präparativ gelang der Nachweis der Isomerisierung eines 3-(tert-Butylamino)-1,3-diaza-2,4-disilacyclobutans (8) zum 1,2,4-Triaza-3,5-disilacyclopentan (9). Lithiumsalze von Silylhydrazinen reagieren mit Fluorsilanen unter Substitution (10 - 15). Dilithiiertes Hydrazin reagiert mit Me2SiF2 zu N(SiFMe2)3 (16). Die Bildung von isomeren N-(Fluorsilyl)-N,N′-bis(trimethylsilyl)- und N′-Fluorsilyl-N,N-bis(trimethylsilyl)hydrazinen wird durch Ringschlußreaktionen (17 - 19) nachgewiesen und durch die Kristallstrukturuntersuchung eines Kreuz-Dimeren-Fünfrings belegt (19). Der zehngliedrige Bicyclus 22 entsteht in der Reaktion des N,N′-Bis(fluordimethylsilyl)-N,N′-bis(trimethylsilyl)hydrazins(14) mit dilithiiertem Hydrazin.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831160133
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  • 4
    Electronic Resource
    Electronic Resource
    Additionsreaktionen von 1,1-Dicyan-2,2-bis(trifluormethyl)ethen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3150-3157 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition Reactions of 1,1-Dicyano-2,2-bis(trifluoromethyl)etheneBy the reaction of the title compound (CF3)2C=C(CN)2 with PCl5 the (phosphoranyliden-amino)ethene 1 is obtained. The phosphorane 1 reacts with Me3SiNMe2 to form 2. WCl6 and MoCl5 react with (CF3)2C=C(CN)2 to give the acyclic nitrenes 3 and 4. The X-ray structure analysis of 3a, an acetonitrile adduct of 3, is reported.
    Notes: Die Titelverbindung (CF3)2C=C(CN)2 reagiert mit PCl5 zu dem (Phosphoranylidenamino)-ethen 1. Daraus entsteht 2 durch Reaktion mit Me3SiNMe2. Umsetzungen von (CF3)2C=C(CN)2 mit WCl6 und MoCl5 ergeben die acyclischen Nitrenkomplexe 3 und 4. Von 3a, einem Acetonitriladdukt von 3, wird eine Röntgenstrukturanalyse mitgeteilt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861191022
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  • 5
    Electronic Resource
    Electronic Resource
    Carben-analoge Reaktionen der Dehalogenierungsprodukte von Dichlor(diisopropylamino)boran mit Aromaten und 1,2-Dimethoxyethan (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 1437-1439 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbene-Analgous Reactions of the Products of Dehalogenation of Dichloro(diisopropylamino)borane with Aromatic Compounds and 1,2-DimethoxyethaneSodium complexes of aromatic compounds in 1,2-dimethoxyethane react with dichloro-diisopropylamino)borane to give compounds formed via carben(oidal) intermediates: From naphthalene 1,2-bis(diisopropylamino)-1,1a,2,8b-tetrahydroborireno[2,3-b][3]benzoborepine (1) is formed. From acenaphthylene 2-(diisopropylamino)-2,3-dihydro-1H-naphtho[1,8-cd]borine (2) and with 1-methylnaphthalene, in addition to 1,2-bis[(diisopropylamino)methoxyboryl]ethyne (3), (diisopropylamino)dimethoxyborane (4) is isolated. 1H-, 11B-, 13C-, 14N-, 15N NMR and MS data are given. For 3 the X-ray structure is reported.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19871200823
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  • 6
    Electronic Resource
    Electronic Resource
    Benzamidinatokomplexe mit Haupt- und Nebengruppen-Elementen - Strukturen von PhC(NSiMe3)2TiCl2 und PhC(NSiMe3)2MoO2 (1988)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 1403-1406 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Benzamidinato Complexes of Main Group and Transition Metals - Crystal Structures of PhC(NSiMe3)2TiCl2 and PhC3)2MoO2PhC(NSiMe3)2Li (3b) reacts with SiCl4, SnCl4, Me2SnCl2, Ph2SnCl2, TiCl4, ZrCl4, MoO2Cl2, and WO2Cl2 with formation of LiCl to yield the new amidinato complexes 4a-f, 5a and 5b. The X-ray structure analyses of 4e and 5a are reported.
    Notes: PhC(NSiMe3)2Li (3b) reagiert mit SiCl4, SnCl4, Me2SnCl2, Ph2SnCl2, TiCl4, ZrCl4, MoO2Cl2 und WO2Cl2 unter Bildung von LiCl zu den Amidinatokomplexen 4a-f, 5a und 5b. Von 4e und 5a wird die Röntgenstrukturanalyse mitgeteilt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19881210807
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  • 7
    Electronic Resource
    Electronic Resource
    (Perfluoralkyl)(dimethylamino)sulfonium-hexafluoroarsenate (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 31-38 
    Details
    ISSN: 0009-2940
    Keywords: Fluorosulfonium salts, reaction with nucleophiles ; (Perfluoroakyl)(dimethylamino)sulfonium salts, preparation and structures of ; Methoxysulfinyl hexafluoroarsenate, alkylation with ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Perfluoroalkyl)(dimethylamino)sulfonium HexafluoroarsenatesMeN = S(CF3)2 (5) is alkylated by Me3O⊕ AsF⊖6 to Me2N-S(CF3)⊕2 AsF⊖6 (4). From 5 and MeOSO⊕ AsF⊖6 (6) MeOS(O)-N(Me)S(CF3)⊕2 AsF⊖6 (7) is formed as a relatively stable primary product. Decomposition of 7 gives the expected 4 only in poor yield. Nucleophilic substitution of the sulfur-bonded fluorine in CF3SF⊕2 AsF⊖6 (8) by Me3SiNMe2 yields CF3S(NMe2)⊕2 AsF⊖6 (9). Similarly, (CF3)2CFSF⊕2 AsF⊖6 (10) reacts with dimethyl(trimethylsilyl)amine to give (CF3)2CFS(NMe2)⊕2 AsF⊖6 (11). The structures of 4 and 9 are elucidated by X-ray analyses, and the influence of the substituents on the bonding is discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911240106
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  • 8
    Electronic Resource
    Electronic Resource
    N,N′-Dilithiobis(alkylamino)phenylborane als Synthesebausteine für viergliedrige Metallacyclen (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 703-706 
    Details
    ISSN: 0009-2940
    Keywords: 4,4′-Spirobi(1,3-diaza-2-bora-4-metallacyclobutanes)/1,3-Diaza-2-bora-4-metallacyclobutanes/Metallaheterocycles with Ge, Sn, Ti, Zr ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N,N′-Dilithiobis(alkylamino)phenylboranes as Starting Materials for Four-Membered MetallacyclesReactions of N,N′-Dilithiobis(alkylamino)phenylboranes with tetrachlorides MCl4 (M = Ge, Sn, Ti, Zr) produce the 4,4′-spirobi(1,3-dialkyl-2-phenyl-1,3-diaza-2-bora-4-metalla-cyclobutane) derivatives 1a, 1b, 2b, 3a, and 3b. With diorganylmetal dihalides R2MX2(M = Sn, Zr; X = Cl, Br), the 1,3-diaza-2-bora-4-metallacyclobutanes 2a and 4 are obtained. For 3a an X-ray structure analysis has been performed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230409
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  • 9
    Electronic Resource
    Electronic Resource
    Synthesis and Molecular Structure of the Solvent-Free [LiN(SiMe3)(2,6iPr2C6H3)]2 Dimer (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2223-2225 
    Details
    ISSN: 0009-2940
    Keywords: Lithium, two-coordinate ; Lithium-nitrogen heterocycle ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [LiN(SiMe3)Ar]2 (1, Ar = 2,6-iPr2C6H3) is prepared by the reaction of HN(SiMe3)Ar with nBuLi in n-hexane. This compound with an unusual structure contains a four-membered [LiN]2 heterocycle with two solvent-free two-coordinate Li centers. Its molecular structure represents the first solid-state X-ray analysis of an uncomplexed [LiN]2 dimer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241013
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  • 10
    Electronic Resource
    Electronic Resource
    Synthese und Struktur von CpAlCl2-Verbindungen mit sterisch anspruchsvollen Substituenten (Cp = Me5C5, EtMe4C5) (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 1107-1109 
    Details
    ISSN: 0009-2940
    Keywords: Bulky substituents ; Aluminum compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Structure of CpAlCl2 Compounds with Sterically Demanding Substituents (Cp = Me5C5, EtMe4C5)[1]The compounds Cp*AlCl2 (3) (Cp* = Me5C5) and Cp′AlCl2 (4) (Cp′ = EtMe4C5) have been prepared by the reaction of Cp*SiMe3 (1) and Cp′SiMe3 (2) with AlCl3. The single-crystal X-ray structures of 3 and 4 are reported.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921250520
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