Tri- and tetravalent titanium alkyls supported by organic amides

The reactions of both trivalent [(Cy(2)N)(2)Ti(mu-Cl)(2)Li(TMEDA)] (1) and tetravalent [(Cy(2)N)(2)-TiC1(2)] (5) with R'Li in THF or diethyl ether gave Ti(IV) complexes (Cy(2)N)(2)TiR'(2) [R' = CH2-CMe(3) (7), CH(2)CMe(2)Ph (8), CH(2)SiMe(3) (9)]. Conversely, the reactions of 1, [{(i-Pr)(2)N}2TiCl2][Li(TMEDA)(2)] (2), and [{(Me(3)Si)(2)N}2TiCl2][Li(TMEDA)(2)] (3) with R'Li [R' = Me, Ph, CH(2)Ph] gave the corresponding trivalent derivatives [(Cy(2)N)(2)Ti(mu-Bz)(2)Li(TMEDA)] (4a), [(Cy(2)N)(2)Ti(mu-Me)(2)Li(TMEDA)] (4b), [{(i-Pr)(2)N}(2)TiPh(2)][Li(TMEDA)(2)] (11), and [{(Me(3)Si)(2)N}Ti-2-(CH(2)Ph)(2)][Li(TMEDA)(2)] (12) via simple ligand replacement reactions. Oxidation of 12 with diphenylfulvene gave {(Me(3)Si)(2)N}Ti-2(CH(2)Ph)(2) (13). All these compounds are thermally labile and yielded intractable materials upon thermolysis. Only in the case of the neophyl derivative (Cy(2)N)(2)Ti(CH(2)CMe(2)C(6)H(5))(2) (8) a cyclometalated compound (Cy(2)N)(2)Ti(CH2-CMe(2)C(6)H(4)) (10) was isolated and crystallized from the thermolyzed solution. The reaction of 1 with styrene oxide provided the Ti-oxo complex [(Cy(2)N)(2)TiCl]O-2 (14) which gave, upon alkylation with MeLi, the corresponding dinuclear alkyl derivatives [(Cy(2)N)(2)TiMe]O-2 (15). The molecular structures of 1 and 10-14 were demonstrated by X-ray diffraction analysis,