The reactions of both trivalent[(Cy2N)2Ti(MG SRC="/images/entities/mgr.gif">-Cl)2Li(TMEDA)](1) and tetravalent[(Cy2N)2TiCl2] (5) with R'Li in THF or diethyl ethergave Ti(IV) complexes(Cy2N)2TiR'2 [R' =CH2CMe3 (7),CH2CMe2Ph (8),CH2SiMe3 (9)].Conversely, the reactions of 1,[{(i-Pr)2N}2TiCl2][Li(TMEDA)2](2), and[{(Me3Si)2N}2TiCl2][Li(TMEDA)2](3) with R'Li [R' = Me,Ph, CH2Ph] gave the corresponding trivalentderivatives[(Cy2N)2Ti(mages/entities/mgr.gif">-Bz)2Li(TMEDA)](4a),[(Cy2N)2Ti(mages/entities/mgr.gif">-Me)2Li(TMEDA)](4b),[{(i-Pr)2N}2TiPh2][Li(TMEDA)2](11), and[{(Me3Si)2N}2Ti(CH2Ph)2][Li(TMEDA)2](12) via simple ligand replacement reactions.Oxidation of 12 withdiphenylfulvene gave{(Me3Si)2N}2Ti(CH2Ph)2(13). All these compounds are thermallylabileand yielded intractable materials upon thermolysis. Only in thecase of the neophylderivative(Cy2N)2Ti(CH2CMe2C6H5)2(8) a cyclometalated compound(Cy2N)2Ti(CH2CMe2C6H4) (10) wasisolated and crystallized from the thermolyzed solution. Thereactionof 1 with styrene oxide provided the Ti-oxo complex[(Cy2N)2TiCl]2O(14) which gave, uponalkylation with MeLi, the corresponding dinuclear alkyl derivatives[(Cy2N)2TiMe]2O(15).The molecular structures of 1 and 10-14were demonstrated by X-ray diffraction analysis.