Collect. Czech. Chem. Commun. 1997, 62, 331-336

Some Reactions of the Products of Reactions of 1,4-Bis(trimethylsilyl)-1,3-butadiyne with Titanoceneand Zirconocene

Vladimir V. Burlakov, Normen Peulecke, Wolfgang Baumann, Anke Spannenberg, Rhett Kempe and Uwe Rosenthal

Arbeitsgruppe "Komplexkatalyse" of the Max-Planck-Gesellschaft, University of Rostock, Buchbinderstr. 5-6, 18055 Rostock, Germany


Bis(η5-cyclopentadienyl)-2,4-bis(trimethylsilylethynyl)-3,5-bis(trimethylsilyl)titanacyclopenta-2,4-diene (1) and the seven-membered zirconacyclocumulene bis(η5-cyclopentadienyl)-2,4,7-tris(trimethylsilyl)-3-(trimethylsilylethynyl)zirconacyclohepta-2,4,5,6-tetraene (2) react with sulfur monochloride to yield an identical product, 2,4-bis(trimethylsilylethynyl)-3,5-bis(trimethylsilyl)thiophene (3). A one-to-one mixture of the homo- and heterobimetallic bis-σ,π-acetylide bridged complexes Cp2Ti(μ-η12-CCSiMe3)M(μ-eta12-CCSiMe3)Cp2 (M = Zr (4), M = Ti (5)) is formed in the reaction of zirconacyclocumulene 2 with three equivalents of Cp2Ti(η2-Me3SiCCSiMe3). The reaction proceeds most likely via alkyne elimination, a C-C-single bond activation, and the cleavage of the starting diyne takes place.

Keywords: Metallocenes; Butadiyne; C-C-Single bond activation; Thiophene.