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  • 1
    Electronic Resource
    Electronic Resource
    Contributions of the Chemistry of Boron, 236. In Quest of New and Stable Bis(organyloxy)boranes (RO)2BH for Catalytic HydroborationDedicated to Prof. Dr. Marianne Baudler on the occasion of her 75th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 363-370 
    Details
    ISSN: 0009-2940
    Keywords: Bis(triphenylmethoxy)hydroborane ; Naphtho[2,3-d], -1,3,2-dioxaborolane ; Naphtho[1,8-de]-1,3,2-dioxaborinane ; Phenanthro[9,10-d]-1,3,2-dioxaborolane ; Dibenzol[d,g]-1,3,2-dioxaborocine ; Bis(diphenylmethoxy)borane ; Tetrachlorobenzo-1,3,2-dioxaboraolen ; Hydroborations ; Boron ; Catalysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New and stable bis(organyloxy)boranes, 1,3,2-dioxaborolanes and 1,3,2-dixoaborinanes have been prepared (i) from the corresponding diol and BH3·THF and (ii) from 1,2-diketones and BH3·THF. They were characterized by spectroscopic techniques. The BH stretching frequency seems to be a measure of ring strain and Lewis acidity. The compounds have been qualitatively tested in the transition-metal-catalysed hydroboration of cyclopentene, and the dioxaborinane 11 proved to be superior to the 1,3,2-dioxaborolanes 9 and 18.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300310
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  • 2
    Electronic Resource
    Electronic Resource
    N-Alkylation of Ammine - Undecahydro-Closo-dodecaborate(1-)Dedicate to Prof. Dr. Walter Siebert on the occasion of hbis 60th birthday. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 795-799 
    Details
    ISSN: 0009-2940
    Keywords: Boron ; Alkylations ; N ligands ; Dodecaborate ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions of the ammine-undecahydro-closo-dodecaborate(1-) anion with alkyl halides have been studied in detail. The degree of alkylation of the nitrogen was found to be dependent upon the steric demands of the alkyl groups. The derivatives were characterized by NMR and infrared spectroscopy. Four compounds were crystallized for single crystal X-ray diffraction studies. The tetrahedral coordination of the nitrogen atom of the bis-alkylated derivatives was found to deviate towards planarity with increasing steric hindrance of the substitutents. - The syntheses, crystal structures, and spectral properties of four N-alkyl derivatives of [H3N—B12H11]-, ammine - undecahydro-closo-dodecaborate(1-) (3), are reported. Alkylation of 3 with ethyl iodide was achieved in dimethyl sulfoxide using potassium hydroxide as base. This led to orthorhombic crystals of [N(nC4H94][(CH3CH2)3N—B12H11] (4). The reaction of 3 with benzyl chloride resulted in the bisbenzylated product, isolated as triclinic crystals of [PPN][(C6H5CH2)2 NH—B12H11] (5). The alkylation of 3 with 2-bromopropane gave a mixture of the mono- and bisalkylated products. The monoalkylated derivative [PPN][(CH3)2CH)NH2-12H11] (6, crystallized in the triclinic space group p1) and the bisalkylated product [PPN]{[(CH3)2NH—B12H11) (7, monoclinic, P21./c) were separated on the basis of their different water solubilities. The solid-state structures of the compounds 4-7 revealed a slight distortion of the B12 icosahedron. The length of the B(1)-N(1) bond was found to be dependent on the steric requirements of the attached amine, e.g. primary amine 〈 secondary amine 〈 tertiary amine. This is demonstrated by the variation in the B—N bond length; from 157.8(2) pm for 6, 158.5(5) pjm for 5, 160.0(3) pm for 7, to 163.7(6) pm for 4.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300619
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  • 3
    Electronic Resource
    Electronic Resource
    Contribution to the Chemistry of Boron, 238Part 237: See ref. Synthesis and Assembly Mechanism for Spirocyclic Cage Compounds Containing, B, P and Si Atoms (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 933-937 
    Details
    ISSN: 0009-2940
    Keywords: Boron ; Phosphorus ; Spiro compounds ; Cage compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 1-lithio · DME-2,4-bis(dialkylamino)-l,3,2,4-diphosphadiboretanes (1a, 1b) with SiCl4 followed by dehydrohalogenation with tBuLi produce spirocyclic compounds [(R2NB)2P2]2Si (2a, 2b). The compounds have been characterized by spectroscopic methods and X-ray crystallography. The assembly process has also been followed and one intermediate species [(iPr2NB)2P2][(iPr2NB)P(H)(iPr2NB)P]SiCl (3) has been isolated and fully characterized.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300719
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    Paper (German National Licenses)
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