340037-49-2Relevant academic research and scientific papers
Syntheses and structures of doubly tucked-in titanocene complexes with tetramethyl(aryl)cyclopentadienyl ligands
Kupfer, Volkmar,Thewalt, Ulf,Ti?lerová, Iva,?těpni?ka, Petr,Gyepes, Robert,Kubi?ta, Ji?í,Horá?ek, Michal,Mach, Karel
, p. 39 - 50 (2001)
Titanocene-bis(trimethylsilyl)ethyne complexes [Ti(η5-C5Me4R)2(η 2-Me3SiC≡CSiMe3)], where R = benzyl (Bz, 1a), phenyl (Ph, 1b) and p-fluorophenyl (FPh, 1c), thermolyse at 150-160°C to give products of double C-H activation [Ti(η5-C5Me4Bz){η 3:η4-C5Me3(CH 2)(CHPh)}] (2a), [Ti(η5-C5Me4Bz){η 3:η4-C5Me2Bz(CH 2)2}] (2a′), [Ti(η5-C5Me4Ph){η 3:η4-C5Me2Ph(CH 2)2}] (2b), and [Ti(η5-C5Me4FPh){η 3:η4-C5Me2FPh(CH 2)2}] (2c). In the presence of 2,2,7,7-tetramethylocta-3,5-diyne (TMOD) the thermolysis affords analogous doubly tucked-in compounds bearing one η3:η4-allyldiene and one η5-C5Me4R ligand having TMOD attached by its C-3 and C-6 carbon atoms to the vicinal methylene groups adjacent to the substituent R (R = Bz (3a), Ph (3b), and FPh (3c)). Compound 3a is smoothly converted into air-stable titanocene dichloride [TiCl2{η5-C5Me2Bz(CH 2CH(t-Bu)CH=CHCH(t-Bu)CH2)}(η5-C 5Me4Bz)] (4a) by a reaction with hydrogen chloride. Yields in both series of doubly tucked-in complexes decrease in the order of substituents: Bz ? Ph > FPh. Crystal structures of 1c, 2a, 2b, and 3b have been determined.
