Thermolysis of titanocene methyl compounds bearing t-butyl- and benzyltetramethylcyclopentadienyl ligands
Abstract
Elimination of methane during thermolysis of title compounds results in the formation of sigma-Ti-C bond to t-butyl or benzyl group. The t-butyl-containing titanocene methyl compound [Ti(III)Me(eta(5)-C(5)Me(4)t-Bu)(2)] (5) eliminates methane at 110 degrees C to give cleanly [Ti(III)(eta(5):eta(1)-C5Me4CMe2CH2)(eta(5)-C(5)Me(4)t-Bu)] (6).
The methyl derivative of analogous benzyl-containing titanocene [Ti(III)Me(eta(5)-C5Me4CH2Ph)(2)] was not isolated because it eliminated methane at ambient temperature to give [Ti(III)(eta(5):eta(1)-C5Me4CH2-o-C6H4)(eta(5)-C5Me4CH2Ph)] (7) with one phenyl ring linked to titanium atom in ortho-position. The corresponding titanocene dimethyl compound [TiMe2{eta(5)-C(5)Me(4)t-Bu)}(2)] (9) eliminates two methane molecules at 110 degrees C to give the singly tucked-in 1,1-dimethylethane-1,2-diyl-tethered titanocene [Ti{eta(5):eta(1):eta(1)-C5Me3(CH2)(CMe2CH2)}(eta(5)-C(5)Me(4)t-Bu)] (11).