Titanium complexes with monoalkyls

Imidazolium ligands, in Rh complexes, 7, 126 Imidazolium salts iridium binding, 7, 349 in silver(I) carbene synthesis, 2, 206 Imidazol-2-ylidene carbenes, with tungsten carbonyls, 5, 678 (Imidazol-2-ylidene)gold(I) complexes, preparation, 2, 289 Imidazopyridine, in trinuclear Ru and Os clusters, 6, 727 Imidazo[l,2-a]-pyridines, iodo-substituted, in Grignard reagent preparation, 9, 37—38 Imido alkyl complexes, with tantalum, 5, 118—120 Imido-amido half-sandwich compounds, with tantalum, 5,183 /13-Imido clusters, with trinuclear Ru clusters, 6, 733 Imido complexes with bis-Gp Ti, 4, 579 with monoalkyl Ti(IV), 4, 336 with mono-Gp Ti(IV), 4, 419 with Ru half-sandwiches, 6, 519—520 with tantalum, 5, 110 with titanium(IV) dialkyls, 4, 352 with titanocenes, 4, 566 with tungsten... 

The alkyl transfer properties of dialkyl zinc reagents have been studied in the reaction of Zn[CH(SiMe3>2]2 with TiCU- The monoalkyl trichloro titanium complex TiCl3[CH(SiMe3)2] was obtained in 83% yield.10... 

When the ligand system consists of chlorine atoms, monoalkyl- and monoaryl-titanium(IV) compounds are readily made from TiCU by a chlorine atom replacement. The parent compound in this series, MeTiCb, is made conveniently from the reaction of TiCU and dimethylzinc without the use of ethereal solvents, the preparation being carried out in n-pentane or dichloromethane. Other methylating species can be used, such as MeMgBr, MeLi and MeAlCh. When MeLi is used in diethyl ether, an equilibrium takes place between different complexation states of Ti in the resulting MeTiCU with the solvent (equation 8). Transmetallation from organotin compounds like (15 equation 9) has also been utilized to make trichlorotitanium compounds. ... 

Styren . Mono-Cp complexes of titanium are especially usefial in the S5m-diotactic polymerization of styrene (first reported in Ref 221, a material with high melting point ( 278°C) and other useful features such as a rapid crystallization rate (222). The catalysts are believed (223) to be cationic Ti(III) monoalkyl species, which then undergo predominantly 2,1-insertions (Scheme 10). This is true even in the case of systems in which the activator is the fluorinated borane B(CeF5)3. The mechanism of reduction is unclear, but appears to be accelerated in the presence of styrene. 

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