Effect of aluminum chloride

Cherroret G, Desor D, Hutin MF, et al. 1996. Effects of aluminum chloride on normal and uremic adult male rats. Biol Trace Elem Res 54 43-53. 

Schetinger MR, Wyse ATS, Da Silva LB, et al. 1995. Effects of aluminum chloride on the kinetics of rat cortex synaptosomal ATP diphosphohydrolase (EC 3.6.1.5). Biol Trace Elem Res 50 209-219. 

Thus, the direct synthesis of phenylchlorosilanes produces a complex mixture, which, apart from phenyltrichlorosilane, diphenyldichlorosilane, phenyldichlorosilane and triphenylchlorosilane, also contains silicon tetrachloride, trichlorosilane, benzene, solid products (diphenyl and carbon) and a gaseous product (hydrogen). It also forms high-boiling polyolefines, which are part of tank residue and can deposit on contact mass, reducing its activity. It should be kept in mind that the production of phenylchlorosilanes requires silicon with a minimal impurity of aluminum, because the aluminum chloride formed contributes to the detachment of the phenyl group from phenylchlorosilanes at higher temperature. The harmful effect of aluminum chloride is counteracted by the addition of metal salts to contact mass, which form a nonvolatile and nonreactive complex with aluminum chloride. 

The so-called Lewis acids (AlCla, SbClg, HgCl2, SnC, etc.) have an effect similar to that of mineral acids. In the case of trityl chloride the effect of aluminum chloride can be represented by the following equation ... 

Aluminum chloride hydroxide [1327-41 -9] also called polyaluminum chloride or PAG, is made by partial hydrolysis of aluminum chloride to form a mixture of polymeric species. It is more expensive than alum on a weight basis, but has advantages over alum such as not lowering the pH as much and better cost-effectiveness in some appHcations. Residual aluminum in the water is said to be lower and performance in cold water is better (6,7). It is sold as a solution (see Aluminum compounds, polyaluminum cm ORiDEs). 

H2SnClg 6H20, CISO H + CH OH, CH COOH, as well as ben2ene-, naphthalene-, and -toluenesulfonic acids (44). Zinc chloride is probably the most frequentiy used catalyst. Its activity is sometimes increased by fusion with a small amount of aluminum chloride. In other instances, however, sufficient catalytic effect is obtained with a mineral acid alone. 

Dinitrogen tetroxide is an effective Eriedel-Crafts nitrating agent (152) for aromatics in the presence of aluminum chloride, ferric chloride, or sulfuric acid (153). Dinitrogen pentoxide is a powerhil nitrating agent, even in the absence of catalysts, preferably in sulfuric acid solution (154). SoHd dinitrogen pentoxide is known to be the nitronium nitrate, (N02) (N02). The use of BE as catalyst has been reported (155). 

Aluminum flufenamate, tris-[2-(3-trifluoromethylphenyl)aminoben2oate]aluminum, is a safer and more effective analgesic than aspirin (94). The dihydroxyalurninum flufenamate is made by reaction of flufenamic acid with aqueous caustic, followed by addition of aluminum chloride with stirring at 42°C for 15 min to give 99% yield (95). Both forms are less irritating and less toxic than the parent acid or aspirin (94,95). 

The reduction of 4-chloro-4-methyltetrahydropyran with triethylsilane requires more than a catalytic amount of aluminum chloride. No 4-methyltetrahydropyran is obtained after 20 hours at room temperature even when 0.75 equivalents of the catalyst is used, but a 92% yield is obtained after only 30 minutes when two equivalents of catalyst and three equivalents of triethylsilane are used.136 146 This is presumably a result of the ability of the Lewis acid to coordinate at the ring oxygen as well as at the chlorine. The introduction of alkyl groups at C2 appears to introduce enough steric hindrance near the ring oxygen to enable less than one equivalent of aluminum chloride to effect reduction, but also makes the products unstable to the reaction conditions so that the synthetic yields decline compared with the unsubstituted substrate.136... 

Direct C-glucosylation can also be effected by boiling methyl a-D-glucopyranoside in benzene in the presence of aluminum chloride and boron trichloride. In this way, 2,3,4,6-tetra-0-acetyl-/3-D-glucopyranosylbenzene was prepared in 32% yield.143 C-Glycosyla-... 

So you can see why branching in the polymerization process can be a problem—the symmetry is affected. And you can get a hint why PP was commercialized long after polyethylene. The chemistry and catalysis are a lot more demanding. Thats why Giulio Natra won the Nobel Prize for his contribution to the field of stereo-catalysis, the discovery of the effects of titanium chloride and organo-aluminum compounds. 

Tetra(tert-butyl)tetrahedrane converts into tetra(tert-butyl)cyclobutadiene only when heated up to 140°C in vacuum. A barrier of 170 kJ mol separates these two isomers (Heilbronner et al. 1980). In the cation-radical state, the tetrahedrane structure converts into the cyclobutadiene structure without heating (Bock et al. 1980, Fox et al. 1982). From Scheme 6.34 it can be seen that by the action of aluminum chloride on methylene chloride, tetrahedrane forms the cation-radical of its isomer—the cyclobutadiene cation-radical and not the cation-radical of the same skeleton. The latter is more stable than the former because of more effective delocalization of the unpaired electron and positive... 

Chloroaluminate ILs derived from l-butyl-3-methylimidazolium chloride having two equivalents of aluminum chloride were effective catalysts for the Pechmann condensation of phenol with ethylacetoacetonate, Scheme 26. ... 

Treatment of veratrole (191) with excess of 2,5-dichloro- (192) or 2,6-dichloro-1,4-benzoquinone in 70% sulfuric acid yields dibenzofurans and other products. Thus 2,5-dichloro-1,4-benzoquinone (192, Scheme 49) affords the dibenzofuran 193, the diarylquinone 194 and the triphenylene 195. The quinol formed by acid-catalyzed addition of veratrole (191) to the quinone 192 is presumably oxidized to the arylquinone 196, which can form the dibenzofuran 193 or undergo further arylation. The quinone 196 is also available by arylation of 2,5-dichloro-1,4-benzoquinone (192) with 3,4-di-methoxybenzenediazonium chloride in buffered solution. On treatment with 70% sulfuric acid, the arylquinone 196 affords the dibenzofuran 193 (88%). The cyclization can also be effected photochemically. The aryl-quinones available by treatment of 2,5- and 2,6-dichloro-1,4-benzoquinones with buffered solutions of diazotized 4-methoxy-3-methyl- and 3-methoxy-4-methylaniline have been cyclized to 2-dibenzofuranols by the agency of aluminum chloride in hot benzene. ... 

Without supporting rate data, it is not possible to exclude a mechanism change of a given reaction when attacking agents are changed. Thus, the benzoylation of copper oxinate can be easily effected when aluminum chloride is used as a catalyst. The acetylation of this same complex has not yet been successfully carried out even under forcing conditions (5). It seems possible that coordination can seriously disrupt the normal path of a reaction when that path involves w complex formation. 

The rate of the second reaction is quite low as long as there is enough free sulfonyl chloride to react with additional amounts of aluminum chloride. Once this is no longer true, further additions of catalyst enormously increase the reaction rate (27). The recently discovered swamping catalyst effect in the halogenation of aromatic donor species (35) probably exhibits analogous kinetic behavior. The basic rate expression found by Olivier consisted of only one term for reaction when a relatively small amount of aluminum chloride was present ... 

The cycloaddition of chloral with 3,3-dimethyl-l-butene to form a good yield of oxetanes can be effected with aluminum chloride catalysis (equation 101). This reaction, however, is not regioselective (72GEP2133564). 

Mechanism. The proven acidity of the effective alkane isomerization catalysts suggests that carbocations are involved in acid-catalyzed alkane isomerization. Such a mechanism was first proposed by Schmerling and coworkers54 on the basis of the pioneering ideas of Whitmore55 for the skeletal isomerization of alkanes and cycloalkanes in the presence of aluminum chloride and a trace of olefin or other promoter. Subsequently these concepts were used to explain the mechanism of the acid-catalyzed isomerizations in general. 

Jensen et al.16 also studied the decomposition of 5-ethoxythiatriazole in dibutyl phthalate solution in the presence of trichloroacetic acid, tripentylamine, 4-benzylpyridine, anhydrous aluminum chloride, or trinitrobenzene, but practically no effect on the reaction rate was observed. However, later experiments have shown that the decomposition can indeed by enhanced catalytically by Lewis acids under conditions where the catalyst is not sequestered by complex formation with the solvent.19 Thus the addition of aluminum chloride to 5-phenylthiatriazole in benzene causes a brisk evolution of nitrogen at room temperature, and if instead boron tribromide is added, a rather violent reaction sets in. However, when esters or ethers are used as... 

Commercial ethylbenzene is manufactured almost exclusively for captive use to produce styrene. Most of the ethylbenzene plants built before 1980 are based on use of aluminum chloride catalysts. Aluminum chloiide is an effective alkylation catalyst but is corrosive. The newer plants are based on zeolite catalysts. 

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