Počet záznamů: 1  

Reduction-induced Double Bond Coordination and Multiple C-H Activation in Fully-substituted Titanocenes Bearing a Pendant Double Bond or an Eight-Membered Hydrocarbyl Ansa-Chain

  1. 1.
    0181589 - UFCH-W 20030014 RIV CH eng J - Článek v odborném periodiku
    Horáček, Michal - Štěpnička, P. - Kubišta, Jiří - Císařová, I. - Petrusová, Lidmila - Mach, Karel
    Reduction-induced Double Bond Coordination and Multiple C-H Activation in Fully-substituted Titanocenes Bearing a Pendant Double Bond or an Eight-Membered Hydrocarbyl Ansa-Chain.
    Journal of Organometallic Chemistry. Roč. 667, 1/2 (2003), s. 154-166. ISSN 0022-328X. E-ISSN 1872-8561
    Grant CEP: GA AV ČR IAA4040004; GA ČR GA203/02/0436
    Výzkumný záměr: CEZ:AV0Z4040901
    Klíčová slova: titanocene * titanuim * X-ray crystallography
    Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
    Impakt faktor: 2.042, rok: 2003

    Reduction of isomeric, fully-substituted titanocene dichlorides having a pendant double bond, [TiCl2(.eta.5-C5Me4R)(.eta.5-C5Me5)] (R = CH2CH2CH=CH2, 1; R = CH(Me)CH=CH2, 2), with magnesium in THF in the presence of bis(trimethylsilyl)ethyne (btmse) affords different products depending on the alkenyl chain length. Whereas the reduction of 1 yields a compound with intramolecularly .eta.2-coordinated double bond, [Ti(.eta.5-C5Me5)(.eta.2:.eta.5-C5Me4(CH2CH2CH=CH2)] (3), compound 2 affords under identical conditions a product with two new Ti-C bonds, [Ti(.eta.1:.eta.1:.eta.5-C5Me3(CH2)(CH(Me)CH2CH2)}(.eta.5-C5Me5)] (4). The formation of 3 can be rationalized as a simple intramolecular stabilization of a titanocene intermediate formed by reductive removal of chloride ligands. The formation of 4 from the respective titanocene, however, requires formally an activation (oxidative addition) of one C-H bond at the methyl group adjacent to the unsaturated chain followed by a hydrogen shift.
    Trvalý link: http://hdl.handle.net/11104/0078133

     
     

Počet záznamů: 1  

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