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  • 1
    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
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  • 2
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 203. Reaktionen einiger Nichtmetallelemente mit 9-Fluorenyliden(2,2,6,6-tetramethylpiperidino)boran (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 963-966 
    Details
    ISSN: 0009-2940
    Keywords: 9-Fluorenyl(2,2,6,6-tetramethylpiperidino)borane ; (9-Bromo-9-fluorenyl)(2,2,6,6-tetramethylpiperidino)boron bromide ; 1,2-Oxaboretane derivative ; 1,2,4,3-Trithiaborolane derivative ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 2031 Reactions of Some Non-Metallic Elements with 9-Fluorenylidene(2,2,6,6-tetramethylpiperidino)borane9-Fluorenylidene(2,2,6,6-tetramethylpiperidino)borane (1) is hydrogenated catalytically at its boron-carbon double bond producing 9-fluorenyl(2,2,6,6-tetramethylpiperidino)borane (2). Similarly, chlorine, bromine, and iodine add to this double bond, but only the bromine adduct 6a has been fully characterized. 1 is oxygen-sensitive. The oxidation product found is the 1,2-oxaboretane derivative 7, which is prepared independently by a [2 + 2] cycloaddition reaction from 1 and 9-fluorenone. Sulfur reacts with 1 to yield a trithiaborolane derivative, while P4 does not attach 1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230504
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  • 3
    Electronic Resource
    Electronic Resource
    Chemistry of Diborane(4) Derivatives: Mixed Tetraaminodiboranes(4) and Additions of Diborane(4) Derivatives to an Amino-imino-borane (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 1605-1611 
    Details
    ISSN: 0009-2940
    Keywords: Diborane(4), tetraamino-, derivatives ; Diborane(4), tetrapiperidino ; 1,2,3,6-Diazadiborinane derivatives ; Haloboration ; Methoxyboration ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several transamination reactions of B2(NMe2)4 (1a) with secondary amines have led to mixed tetraaminodiborane(4) compounds B2(NMe2)4 - n(NR2)n (2-4), and B2(NC5H10)4 (1d) has been characterized by an X-ray structure analysis which reveals the presence of a rather long B-B bond (1.75 Å). However, tetraaminodiboranes(4) of type R2N(Me2N)B-B(NMe2)NR2 are more readily accessible from LiNR2 and B2(NMe2)2Cl2. Similarly, amination of B2(NMe2)2Cl2 with N,N'-dimethylethylenediamine (7) yields B-[bis(dimethyl-amino)boryl]-N,N'-dimethyl-1,3,2-diazaborolidine (8), while reactions with Li(Me)N-CH2-CH2-N(Me)Li (9) lead also to 2,3-bis(dimethylamino)-1,4-dimethyl-1,4,2,3-diazadiborinane (10) as the kinetically controlled product. This is further substantiated by the reaction of the B2(NMe2)2Br2 with 9 which gives exclusively the corresponding 1,4,2,3-diazadiborinane 11. Diborane(4) dihalides B2(NMe2)2X2 (X = Cl, Br) react only in a 1:1 ratio with tmp-B=N-CMe3 (13) leading to 14a, b. However, both a 1:1 and a 1:2 methoxyboration of 13 has been observed with B2(OMe)4 with formation of 15 and 16.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19941270909
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    Paper (German National Licenses)
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