Ethene Elimination during Thermolysis of Bis(3-butenyltetramethylcyclopentadienyl)dimethyltitanium

0371365 - ÚFCH JH 2012 RIV US eng J - Článek v odborném periodiku
Pinkas, Jiří - Gyepes, R. - Kubišta, Jiří - Horáček, Michal - Mach, Karel
Ethene Elimination during Thermolysis of Bis(3-butenyltetramethylcyclopentadienyl)dimethyltitanium.
Organometallics. Roč. 30, č. 9 (2011), s. 2581-2586. ISSN 0276-7333. E-ISSN 1520-6041
Grant CEP: GA AV ČR IAA400400708; GA MŠMT(CZ) LC06070; GA ČR GP203/09/P276
Výzkumný záměr: CEZ:AV0Z40400503
Klíčová slova: TITANIUM COMPOUNDS (ETA-5-C5ME5)2TIR * OLEFIN METATHESIS REACTION * TITANOCENE DICHLORIDES
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 3.963, rok: 2011

Thermolysis of [TiMe(2){eta(5)-C(5)Me(4)(CH(2)CH(2)CH=CH(2))}(2)] (1) in toluene at 120 C for 4 h resulted in the formation of the cyclopentadiene ring-tethered titanacyclobutane [Ti(IV){eta(5)-C(5)Me(4)CH(2)CH(2)CH(kappa-CH)}(2)CH(2)] (2) in virtually quantitative yields. Thermolysis in an NMR tube at 100 C revealed that initial elimination of methane is followed by addition of one 3-butenyl double bond to a titanocene methylidene moiety. The formed titanacyclobutane intermediate [Ti{eta(5)-C(5)Me(4)(CH(2)CH(2)CH=CH(2))} {eta(5)-C(5)Me(4)CH(2)CH(2)CH (kappa-CH)CH(2)CH(2)-(kappa-CH(2))}] (4) then underwent a metathesis reaction with the pendant 3-butenyl to give 2 and free ethene. Cleavage of Ti-C bonds of 2 with HCl afforded stable ansa-[TiCl(2){eta(5)-C(5)Me(4)(CH(2))(7)eta(5))-C(5)Me(4)}] (3). Sunlight photolysis of 1 gave rise to the cyclopentadiene ring-tethered titanacyclopentane [Ti(IV){eta(5)-C(5)Me(4)(CH(2)CH(2)CH(kappa-CH)CH(2)}(2)] (5), the known product of cycloaddition reactions following the removal of chlorine atoms from [TiCl(2){eta(5)-C(5)Me(4)(CH(2)CH(2)CH=CH(2))}(2)] with magnesium (as found by Horaeek, M. et al. Chem. Eur. J. 2000, 6, 2397).
Trvalý link: http://hdl.handle.net/11104/0204899