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  • 1
    Electronic Resource
    Electronic Resource
    Neue Organobor-Sauerstoff-Halogenaluminium-Verbindungen aus Triorganoboroxinen mit Aluminiumtrihalogeniden (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1301-1314 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Organoboron-Oxygen-Halogenaluminium Compounds from Triorganoboroxins with Aluminium Trihalides4 mol of triorganoboroxins (RBO)3 (1) [R = CH3 (1a), C4H5 (1b), C4H9 (1c), C6H5 (1d)] react with 6 mol of aluminium trihalides AlHal3 (2) [Hal = Cl (2a), Br (2b)] under cleavage of 4 mol dihalogenoorganoboranes RBHal2 (3) [Hal = Cl: 3aa (R = CH3), 3ba (R = C2H5), 3ca (R = C4H9), 3da (R = C6H5); Hal = Br: 3bb (R = C2H5)] leading in high yields to 2 mol of compound 4 having the composition R4Al3B4Hal5O6 (MS analyses) [Hal = Cl: 4aa (R = CH3), 4ba (R = C2H5), 4ca (R = C4H9) 4da (R = C6H5); Hal = Br: 4bb (R = C2H5)]. The structure of 4aa, 4ba, 4ca, and 4bb in solution is deduced from spectroscopic data (IR; 1H-, 11B, 17O and 27Al NMR). The molecular structure of the solid (C6H5)4Al3B4Cl5O6 (4da) with two (AlOBOBO)-rings bonded through one penta-coordinated aluminium atom was determined by X-ray diffraction analysis.
    Notes: 4 mol Triorganoboroxin (RBO)3 (1) [R = CH3 (1a), C4H5 (1b), C4H9 (1c), C6H5 (1d)] reagieren mit 6 mol Aluminiumtrihalogenid AlHal3 (2) [Hal = Cl (2a), Br (2b)] unter Abspaltung von 4 mol Dihalogenorganoboran RBHal2 (3) [Hal = Cl: 3aa (R = CH3), 3ba (R = C2H5), 3ca (R = C4H9), 3da (R = C6H5); Hal = Br: 3bb (R = C2H5)] in hohen Ausbeuten zu 2 mol der neuen Verbindungen 4 mit der Zusammensetzung R4Al3B4Hal5O6 (MS-Analysen) [Hal = Cl: 4aa (R = CH3), 4ba (R = C2H5), 4ca (R = C4H9), 4da (R = C6H5); Hal = Br: 4bb (R = C2H5)]. Die Struktur von 4aa, 4ba, 4ca und 4bb in Lösung ermittelte man mit Hilfe spektroskopischer Daten (IR; 1H-, 11B-, 17O- und 27Al-NMR). Die Molekülstruktur des festen (C6H5)4Al3B4Cl5O6 (4da) mit zwei über ein fünffach koordiniertes Aluminium-Atom verknüpften (AlOBOBO)-Ringen wurde durch Röntgenstrahlbeugung bestimmt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190419
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  • 2
    Electronic Resource
    Electronic Resource
    Neuartig chelatisierte Organodiboroxane und Organoboroxine aus Triorganoboroxinen und enolisierbaren 1,3-Diketonen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1931-1952 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Chelated Organodiboroxanes and Organoboroxins from Triorganoboroxins and Enolizable 1,3-DiketonesTrialkylboroxins (RBO)3 (1) [1a: R=CH3; 1b: R=C2H5] react with enolizable 1,3-diketones (R′CO)2CH2 [2a: R′=CH3; 2b: R′=C6H5] at ≈ 20°C with fast degradation of the boroxin rings to give the monochelated diboroxanes 3 of the composition HOB(R)OB(R)OC(R′)CHC(R′)O [3aa: R=R′=CH3; 3ba: R=C2H5, R′=CH3; 3bb: R=C2H5, R′=C6H5] in yields up to 85%. The solid 3 with H-bridged bicyclic structures are in equilibrium with partially ring opened compounds in solution (1H, 11B, 13C, and 17O NMR data). From 1b with 2a or from triphenylboroxin (1c) with 2b the double chelated diboroxanes [RB(R′CO)2CH]2O [4ba: R=C2H5, R′=CH3; 4cb: R=R′=C6H5] are obtained. 1c reacts with 2a or 2b at 〉 140°C under slow protolysis of the B-phenyl residues to form the single and double chelated boroxins 5 and 6 having the compositions R2B3O3(R′CO)2CH [5ca: R=C6H5, R′=CH3; 5cb: R=R′=C6H5] and RB3O3[(R′CO)2CH]2 [6cb. R=R′=C6H5].  -  4, 5, and 6 with fully or partially chelated boron atoms are stable up to 〉 200°C.  -  The molecular structures of 4cb and 5ca were determined by X-ray analyses.
    Notes: Aus Trialkylboroxinen (RBO)3 (1) [1a: R=CH3; 1b: R=C2H5] bilden sich bei ≈ 20°C mit enolisierbaren 1,3-Diketonen (R′CO)2CH2 [2a: R′=CH3; 2b: R′=C6H5] unter raschem Abbau der Boroxin-Ringe in bis zu 85proz. Ausbeute die monochelatisierten Diboroxane 3 der Zusammensetzung HOB(R)OB(R)OC(R′)CHC(R′)O [3aa: R=R′=CH3; 3ba: R=C2H5, R′=CH3; 3bb: R=C2H5, R′=C6H5]. Die festen 3 mit H-verbrückter bicyclischer Struktur stehen in Lösung im Gleichgewicht mit partiell ringgeöffneten Verbindungen (1H-, 11B-, 13C- und 17O-NMR-Daten). Aus 1b erhält man mit 2a und aus Triphenylboroxin (1c) mit 2b die zweifach chelatisierten Diboroxane [RB(R′CO)2CH]2O [4ba: R=C2H5, R′=CH3; 4cb: R=R′=C6H5]. 1c reagiert mit 2a oder 2b bei 〉 140°C unter langsamer Protolyse der B-Phenylreste zu den einfach und zweifach chelatisierten Boroxinen 5 und 6 mit den Zusammensetzungen R2B3O3(R′CO)2CH [5ca: R=C6H5, R′=CH3; 5cb: R=R′=C6H5] und RB3O3[(R′CO)2CH]2 [6cb: R=R′=C6H5]. 4, 5 und 6 mit vollständig bzw. partiell chelatisierten Bor-Atomen sind bis 〉 200°C stabil.  -  Die Molekülstrukturen von 4cb und 5ca wurden durch Röntgenstrahlbeugungsanalysen bestimmt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190615
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  • 3
    Electronic Resource
    Electronic Resource
    Chelat-stabilisierte 1,3-Bis(acyloxy)-1,3-diethyldiboroxane aus Triethylboroxin und Carbonsäureanhydriden115. Mitteilung über Borverbindungen.  -  114. (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 1191-1199 
    Details
    ISSN: 0009-2940
    Keywords: Ethylboronic carboxylic acid anhydrides, comproportionation of ; Bicyclo[3.3.1]nonadienes, heteroatom-containing ; Bicyclo[3.3.3]undecadienes, heteroatom-containing ; 1,3,2-Diboroxanes ; Oxygen atom exchange ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chelate-Stabilized 1,3-Bis(acyloxy)-1,3-diethyldiboroxanes from Triethylboroxin and Carboxylic Acid AnhydridesTriethylboroxin (A) reacts with carboxylic acid anhydrides (RCO)2O [R = Me: 1a; Et: 1b; tBu: 1d; Ph: 1e] with various rates to give high yields of the 3,7-dialkyl-1,5-diethyl-4,8,9-trioxa-2,6-dioxonia-1,5-diboratabicyclo[3.3.1]nona-2,6-dienes OB(Et)OC(R)OB(Et)OC(R)O (2) [R = Me: 2a (X-ray crystal structure analysis); Et: 2b; tBu: 2d; Ph: 2e], presumably via the unstable compounds OB(Et)OB(Et)OC(R)OB(Et)OC(R)O (3a,b, d, e). Compound 1c (R = CF3) reacts with A to form a mixture of 1,3-diethyl-1,3-bis(trifluoroacetoxy)diboroxane O=C(CF3)OB(Et)OB(Et)O(CF3)C=O (2c′) and 2c (R = CF3) at room temperature. Whereas two compounds of the type 2 do not comproportionate, 1a-e spontaneously form the mixed substituted carboxylic acid anhydrides 1ab etc. on mixing at room temperature (GC, 13C NMR). - From the 17O-enriched A* and 1a-e the 17O-enriched compounds 2a*-e* with BO*B and YYBO*OCR groups are obtained. A* exchanges O atoms up to 200°C with succinic anhydride (1f) forming 1f* or with phthalic acid anhydride (1g) forming 1g* and 3g*. - The mixed carboxylic acid anhydrides 1xy are cleaved, and the mixtures of 1 are separated with A to yield the uniform 3,7-dialkyl-substituted compounds 2.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19941270704
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