Oxidation reactions titanium tetrachloride

In this process, catalysts, such as boric acid, molybdenum oxide, zirconium, and titanium tetrachloride or ammonium molybdate, are used to accelerate the reaction. The synthesis is either carried out in a solvent (aUphatic hydrocarbon, trichlorobenzene, quinoline, pyridine, glycols, or alcohols) at approximately 200°C or without a solvent at 300°C (51,52). 

Many other reactions of ethylene oxide are only of laboratory significance. These iaclude nucleophilic additions of amides, alkaU metal organic compounds, and pyridinyl alcohols (93), and electrophilic reactions with orthoformates, acetals, titanium tetrachloride, sulfenyl chlorides, halo-silanes, and dinitrogen tetroxide (94). 

The formation of carbon monoxide aids chlorination in exactly the same way as does the formation of carbon dioxide which of the two oxides of carbon would found in the reaction depends on the temperature at which reduction-chlorination is carried out. Below 600 °C carbon dioxide forms while above 700 °C carbon monoxide is formed. This changeover results from the variation in the free energies of formation of these two oxides with temperature. For example, at 900 °C the situation as regards the formation of titanium tetrachloride from titanium dioxide is guided by the reactions ... 

Titanium tetrachloride is produced on an industrial scale by the chlorination of titanium dioxide-carbon mixtures in reactors lined with silica. During the reactor operation, the lining comes into contact not only with chlorine but also with titanium tetrachloride. There appears to be no attack on silica by either of these as the lining remains intact. However, the use of such a reactor for chlorinating beryllium oxide by the carbon-chlorine reduction chlorination procedure is not possible because the silica lining is attacked in this case. This corrosion of silica can be traced to the attack of beryllium chloride on silica. The interaction of beryllium chloride with silica results in the formation of silicon tetrachloride in accordance with the reaction... 

It follows that titanium tetrachloride can not chlorinate silica because at all temperatures the free energy change for that reaction has a large positive value. In general, in the interaction between the oxide (MO) of one metal (M) and the chloride (M C12) of a different metal (M ) ... 

More traditional carbon nucleophiles can also be used for an alkylative ring-opening strategy, as exemplified by the titanium tetrachloride promoted reaction of trimethylsilyl enol ethers (82) with ethylene oxide, a protocol which provides aldol products (84) in moderate to good yields <00TL763>. While typical lithium enolates of esters and ketones do not react directly with epoxides, aluminum ester enolates (e.g., 86) can be used quite effectively. This methodology is the subject of a recent review <00T1149>. 

Presently there are two main processes for manufacturing this important white pigment. The main one involves reaction of rutile ore (about 95% Ti02) with chlorine to give titanium tetrachloride. For this reason we have chosen to group this key chemical under chlorine and sodium chloride. The titanium tetrachloride is a liquid and can be purified by distillation, bp 136°C. It is then oxidized to pure titanium dioxide and the chlorine is regenerated. Approximately 94% of all titanium dioxide is made by this process. 

The Schmidt reaction affords both possible isomers when applied at the sulfide oxidation level, and also with the sulfoxide, no trace of sulfoximine being found (75CJC276). Reduction of the oxime to the amine with lithium aluminum hydride is significantly improved by the presence of titanium tetrachloride (78KGS1694). 

The principal use for the tetrachloride is in pyrots as a smoke agent (called FM ), Ref 5 reports that the tetrachloride. . is extremely reactive resulting in the formation of hydrated oxides, or with atmospheric moisture and, when used for screening, is often disseminated from aircraft spray tanks. Its reaction with water vapor is relatively complex. First, the titanium tetrachloride is hydrated. This reaction is followed by further hydrolysis yielding, finally, titanium hydroxide and HC1. The smoke consists of a mixture of fine particles of solid titanium hydroxide, Ti(0H)4 the hydrated oxide, Ti02-H20 intermediate hydroxychlorides of titanium and dilute HC1 droplets. The sequence of reaction is ... 

Syntheses of MPc from phthalodinitrile or phthalic anhydride in the presence of urea are the two most important laboratory and industrial methods. They were also used originally by Linstead et al. [8,9], This procedure allows the production of many phthalocyanine compounds [35-37], Catalysts such as boric acid, molybdenum oxide, zirconium and titanium tetrachloride, or ammonium molybdate are used to accelerate the reaction and improve the yield [36,37], Ammonium molybdate is especially effective. Reaction is carried out either in a solvent or by heating the solid components. When metal chlorides and phthalodinitrile are used as starting materials, the reaction products are partially chlorinated (e.g.,7). 

Diaryl tellurium oxides were converted to diaryl tellurium dichlorides through reactions with carboxylic acid chlorides4, tin tetrachloride, titanium tetrachloride, or antimony pentachloride5. 

As previously mentioned, 1-alkynyltrialkylborates (18) have become increasingly important in the formation of carbon-carbon bonds via attack of electrophiles. However, such complexes cannot react with simple Qc,P-unsaturated carbonyl compounds such as methyl vinyl ketone, because of their weak electrophilicity. Recently it was ascertained that ,P-unsaturated carbonyl compounds react with 18 via a Michael-type reaction in the presence of titanium tetrachloride, and the usual alkaline hydrogen peroxide oxidation leads to the synthesis of 5-dicarbonyl compounds... 

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