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Aluminum alkyls reactions with

Brown and Grayson reported that the rate of alkylation reactions with benzyl chloride was third order overall first order in aromatic component, first order in AICI3, and first order in benzyl chloride. This indicates that a rate determining nucleophilic attack by the aromatic component on a polar alkyl chloride-aluminum... [Pg.149]

The results of these alkylation reactions with allyidichlorosilane (1) in the presence of aluminum chloride catalyst are summarized in Table II. [Pg.151]

With increasing temperature the As-B adducts convert to the N-B adduct, except for the i-Pr compound, which is stable at room temperature, and decomposition leads to the formation 0fMe2AsAsMc2, Mc2AsH, [R2NBH2]2, andR2NH-BH3. The results from the aluminum alkyl reactions have been used to develop new syntheses to tertiary arsines (see Section 2). [Pg.261]

In commercial polyethylene operations, poisons may enter the process as trace (ppm) contaminants in ethylene, comonomer, hydrogen (CTA), nitrogen (used as inert gas), solvents and other raw materials. These poisons reduce catalyst activity. Most damaging are oxygen and water. However, CO, CO, alcohols, acetylenics, dienes, sulfur-containing compounds and other protic and polar contaminants can also lower catalyst performance. With the exception of CO, aluminum alkyls react with contaminants converting them to alkylaluminum derivatives that are less harmful to catalyst performance. Illustrative reactions of contaminants with triethylaluminum are provided in eq 4.9-4.11 ... [Pg.50]

Much effort has been devoted during the last 30 years toward understanding the mechanisms operative in the coordination catalysis of ethylene and a-olefin polymerization using Ziegler-Natta systems (metal halide and aluminum alkyl, sometimes with Lewis base modifiers). Aspects of the complex heterogeneous reactions have been elucidated (jL- ) but the intimate mechanistic detail - for example the role of inhibitors and promoters, kinetics and thermodynamics of chain growth, modes of chain transfer and termination - comes primarily from studies of homogeneous catalysts ... [Pg.459]

Ziegler and Gellert (6) in 1949 showed that aluminum hydride reacts with ethylene at 60-80 °C to yield triethylaluminura. At 100-120 C reaction with additional ethylene leads to formation of higher alkyls of aluminum (Reaction 1). At temperatures above 120 C higher aluminum alkyls react with ethylene through a... [Pg.69]

Due to thdr ubiquitous presence in transition metal-catalyzed polymerization reactions, alkyl aluminum compounds as protective groups are extensively smdied. Their effect is based on the reaction of aluminum alkyl compounds with Lewis basic (and therefore catalyst poisoning) oxygen or nitrogen atoms of the monomers (Scheme 13). As a result, coordinative poisoning of the catalyst is prevented in subsequent polymerization reactions. [Pg.796]

Styrene is produced mainly by catalytic dehydrogenation of high-purity ethylbenzene in the vapor phase. A typical integrated process scheme for the manufacture of styrene and ethylbenzene is shown in Fig. 22.17, in the earlier section on ethylbenzene. The alkylation reaction, with excess benzene, takes place in a homogeneous system with an aluminum chloride catalyst. The ethylbenzene dehydrogenation also is catalytic, using a commercially available catalyst. The fractionation train separates high-purity styrene, unconverted ethylbenzene, and minor reaction by-products such as toluene. [Pg.849]

There are two important side reactions, particularly above 120°C (/) aluminum alkyls decompose to form diaLkylalurninum hydrides and alpha olefins (the diaLkylalurninum hydrides rapidly react with ethylene to regenerate a trialkylalurninum) ... [Pg.456]

The other commercially important routes to alkyltin chloride intermediates utilize an indirect method having a tetraalkjitin intermediate. Tetraalkyltins are made by transmetaHation of stannic chloride with a metal alkyl where the metal is typicaHy magnesium or aluminum. Subsequent redistribution reactions with additional stannic chloride yield the desired mixture of monoalkyl tin trichloride and dialkyltin dichloride. Both / -butjitin and / -octjitin intermediates are manufactured by one of these schemes. [Pg.547]

Methylphenol is converted to 6-/ f2 -butyl-2-methylphenol [2219-82-1] by alkylation with isobutylene under aluminum catalysis. A number of phenoHc anti-oxidants used to stabilize mbber and plastics against thermal oxidative degradation are based on this compound. The condensation of 6-/ f2 -butyl-2-methylphenol with formaldehyde yields 4,4 -methylenebis(2-methyl-6-/ f2 butylphenol) [96-65-17, reaction with sulfur dichloride yields 4,4 -thiobis(2-methyl-6-/ f2 butylphenol) [96-66-2] and reaction with methyl acrylate under base catalysis yields the corresponding hydrocinnamate. Transesterification of the hydrocinnamate with triethylene glycol yields triethylene glycol-bis[3-(3-/ f2 -butyl-5-methyl-4-hydroxyphenyl)propionate] [36443-68-2] (39). 2-Methylphenol is also a component of cresyHc acids, blends of phenol, cresols, and xylenols. CresyHc acids are used as solvents in a number of coating appHcations (see Table 3). [Pg.67]

Aluminum chloride dissolves readily in chlorinated solvents such as chloroform, methylene chloride, and carbon tetrachloride. In polar aprotic solvents, such as acetonitrile, ethyl ether, anisole, nitromethane, and nitrobenzene, it dissolves forming a complex with the solvent. The catalytic activity of aluminum chloride is moderated by these complexes. Anhydrous aluminum chloride reacts vigorously with most protic solvents, such as water and alcohols. The ability to catalyze alkylation reactions is lost by complexing aluminum chloride with these protic solvents. However, small amounts of these "procatalysts" can promote the formation of catalyticaHy active aluminum chloride complexes. [Pg.147]

Reactions other than those of the nucleophilic reactivity of alkyl sulfates iavolve reactions with hydrocarbons, thermal degradation, sulfonation, halogenation of the alkyl groups, and reduction of the sulfate groups. Aromatic hydrocarbons, eg, benzene and naphthalene, react with alkyl sulfates when cataly2ed by aluminum chloride to give Fhedel-Crafts-type alkylation product mixtures (59). Isobutane is readily alkylated by a dipropyl sulfate mixture from the reaction of propylene ia propane with sulfuric acid (60). [Pg.199]

Aluminum alkyls react by the Ziegler reaction with the least substituted double bond to give the tricitroneUyl aluminum compound. Oxidation of the iatermediate compound then produces the tricitroneUyl aluminate, which is easily hydroly2ed with water to give citroneUol (112,113). If the citroneUene is opticaUy active, opticaUy active citroneUol can be obtained (114). The (—)-citroneUol is a more valuable fragrance compound than the ( )-citroneUol. [Pg.419]

Cumene as a pure chemical intermediate is produced in modified Friedel-Crafts reaction processes that use acidic catalysts to alkylate benzene with propylene (see Alkylation Friedel-CRAFTSreactions). The majority of cumene is manufactured with a soHd phosphoric acid catalyst (7). The remainder is made with aluminum chloride catalyst (8). [Pg.363]

In the production of a-olefins, ethylene reacts with an aluminum alkyl at relatively low temperature to produce a higher aLkylalumiaum. This is then subjected to a displacement reaction with ethylene at high temperatures to yield a mixture of a-olefins and triethylalumiaum. In an alternative process, both reactions are combiaed at high temperatures and pressures where triethylalumiaum fuactioas as a catalyst ia the polymerization process. [Pg.433]


See other pages where Aluminum alkyls reactions with is mentioned: [Pg.840]    [Pg.708]    [Pg.280]    [Pg.42]    [Pg.50]    [Pg.42]    [Pg.50]    [Pg.127]    [Pg.162]    [Pg.72]    [Pg.152]    [Pg.161]    [Pg.213]    [Pg.211]    [Pg.55]    [Pg.93]    [Pg.515]    [Pg.411]    [Pg.412]    [Pg.437]    [Pg.437]    [Pg.218]    [Pg.128]    [Pg.480]    [Pg.111]    [Pg.154]    [Pg.372]    [Pg.174]   


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Alkyl halides, reaction with aluminum

Alkyl reaction with

Aluminum alkyls

Aluminum alkyls reaction with propylene

Aluminum alkyls reactions

Aluminum reaction with

Halides, alkyl reaction with aluminum hydride reagents

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