Using TiCl,

Synthesis of ETS-10 using TiCls and crystalline Ti02 (anatase) as Ti sources. Gel composition 4Na20 1.5K20 Ti02 5.5Si02 125H20. Crystallization at 503 K for 24 h... 

Moreover MWD is broadened also with an increase in the number of electron acceptor ligands, for example varying x from 0 to 4 by using TiCl (On—Bu) as transition metal compound... 

Thus, polymer chains —(CH2CHR ) — are created. This is an important route to polypropylene (polypropene, in the newer nomenclature R = CH3), which is difficult to make by other methods. Furthermore, it was shown by G. Natta that the heterogeneous (Ziegler-Natta) catalysts prepared using TiCls in place of TiCU produced polymers in which the side groups R were arranged in a regular manner in relation to the central carbon chain (Fig. 18.4). 

Trichlorotitanium enolates are formed in variable yield from trimethylsilyl enol ethers and an equivalent of TiCU in dichloromethane at 20-35 C.27 These highly Lewis acidic preformed enolates then undergo aldol reactions at -70 °C to give moderate levels of syn selectivity, as in equation (13).28 Trichlorotitanium enolates have also been used by Reetz et al. in their studies on diastereofacially selective aldol additions to ot-alkoxy aldehydes.15,16 Trichlorotitanium enolates are formed in situ in the aldol reaction of aromatic ketones and aldehydes using TiCL and EtsN.29... 

To lower the deposition temperature, CVD processes enhanced by plasma [48-58] and laser [55-58] have been investigated. Low-resistivity (< 40 pQ cm) TiN was deposited by Akahori et al. [59] using TiCL in an electron-cyclotron resonance (ECR) plasma process (Ts b = 540°C, microwave power = 2.8 kW). All films had stoichiometric composition with low chlorine concentrations of 0.16 at. % as determined by ICP-MS. This indicates that the nitridation reaction of TiCU is enhanced enormously by the ECR plasma. 

Aldol and Dieckmann reactions These condensation reactions are readily achieved using TiCL -Bu3N and a catalytic amount of Me SiCl. The effectiveness of the reagent system can be gauged by the reaction conditions (e.g., cyclization of dimethyl adipate in dichloromethane at —78° affords methyl 2-oxocyclpentanecarboxylate in 95% yield). 

The copolymerization of propylene and allyl alcohol has been reported using TiCls/ethyl aluminum ses-quichloride catalyst. The resulting polymer contained about 4 wt % of the allyl alcohol and an isotactic fraction of about 98%. Catalyst activities, however, were very low (ca. 320 g of PP/g of Ti h atm) (eq 3). 

Later, p-acetoxy-substituted cyclic enones 87 with various ring sizes were also examined for intramolecular Stetter cyclization. Under the optimized Stetter conditions (1.0 equiv. of thiazolium salt 88 and 1.2 equiv. of EtsN in EtOH under reflux), bicyclic enedione 89 could be synthesized effectively (Scheme 4.27), but the yields mainly depended on the size of the ring in the substrate 87." Increasing the substrate ring size led to improved yields of 89. Cycloheptenone and cyclooctenone derivatives 87c,d afforded the desired enediones 89c,d in 80% yields. To reduce the conjugated C-C double bond, McMurry s procedure" using TiCls as a reductant was employed to give diketones 90 in excellent yields. 

Ackennann used TiCl with f-BuNH as a catalyst for the hydroamination of alkynes with hydrazines, leading to indoles. Three examples of this nice Fischer indolization are shown in equations 4 to 6 [103],... 

Smith, G.D. and Boyd, R.H. (1992) Subglass relaxations - Intermolecular packing and the relaxation-times for ester side group reorientation - a Molecular-dynamics simulation. Macromolecules 25,1326-1332. Mani, R. and Burns, C.M. (1991) Homo- and copolymerization of ethylene and styrene using TiCl ... 

Heterogeneous catalysts are suspended in the solvent. The Ziegler catalyst TiCl A1(C2H5)3 affords polypropene with very low stereospecifity (compare Table 14). One criterion for the determination of stereospecifity is the isotacticity index, which is defined as the percentage of polymer that is insoluble in boiling heptane [10]. Natta achieved a substantial increase in stereoselectivity by using TiCls instead of TiCl4 [240]. 

Table 2 Sununary of copolymerization reactions between propylene or 1-octene and 5-hexenyl-9-BBN using TiCls AA/Et2AlCl catalyst...

In 1957, D. B. Ludlum and coworkers at the E. I. DuPont Company published an early paper on the characteristics of the Mulheim catalyst [11], Ludlum investigated the polymerization of ethylene in a high-boiling inert solvent (decalin) using TiCl and tri-isobutylaluminum (TIBA), Tri-n-hexyl aluminum (THA) or triethylaluminum (TEAL) at 100 C and 1-1.5 atm of ethylene pressure. The rate of ethylene uptake was found to decrease shortly after polymerization was initiated and Lunlum postulated that this was due to the encapsulation of polymerization sites by the polyethylene. The polymerization was also found to be first-order with regard to the ethylene pressure and the concentration of TiCl. The effect of the Al/Ti ratio on catalyst activity and the type of aliuninum alkyl used (TIBA or TEAL) in the polymerization are shown in Figure 2.1. 

Ar. halogenation of overactive substrates such as acetanilides has been performed smoothly by using TiCl in the presence of an oxidant . Very reactive heterocyclics have been brominated with 2,4,4,6-tetra-bromo-2,5-cyclohexadienone . 

Valizadeha H, Shockravi A (2005) An efficient procedure for the synthesis of coumarin derivatives using TiCL as catalyst under solvent-free conditions. Tetrahedron Lett 46 3501-3503... 

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