Diethyl aluminum

DICLORCAL 50 , dichlorvos, 53 Dicofol, 53 Dicrotophos, 53 Dicyclohexylamine, 53 Dicyclohexylamine nitrite, 53 Dicyclopentadiene, 53 Dicyclopentadienyl bon, 53 Dieldrin, 54 Diepoxybutane, 54 Diethanolamine, 54 Diethoxypropene, 54 Diethyl aluminum chloride, 54 Diethylamine, 54 Diethylaminoethanol, 54... 

Pyrolysis of diethyl aluminum azide [(C2H5)2A1N3] at 450-870°C). 

The pyrolysis of aluminum-nitrogen organic complexes, such as diethyl aluminum azide [(C2H5)2A1N3], is also used successfully at low deposition temperatures (450-870°C).0 l Another metallo-organic, hexakis(dimethylamido)dialuminum, reacting with ammonia allows deposition at 200-250°C at atmospheric pressure. 1... 

This procedure, which is based on the work of Ishii and co-workers, affords a mild and general method for converting a wide variety of esters to primary, secondary, and tertiary amides (Table 1). While the preparation of the tertiary amide, N,N-dimethylcyclohexanecarboxamide, described here is carried out in benzene, aluminum amides derived from ammonia and a variety of primary amines have been prepared by reaction with trimethylaluminum in dichloromethane and utilized for aminolysis in this solvent. Although 1 equivalent of the dimethylaluminum amides from amines was generally sufficient for high conversion within 5-48 hours, best results were obtained when 2 equivalents of the aluminum reagent from ammonia was used. Diethyl-aluminum amides can also effect aminolysis, but with considerably slower rates. 

Figure 15—3 lays out the four-step process, starting with germinating the seed from which everything sprouts. Triethyl aluminum is created from aluminum, hydrogen, and ethylene in step one, which itself has several parts. Powdered aluminum in a toluene slurry is fir-st converted to diethyl aluminum hydride, HA1(C2H5)2, at 212—300 F and 1500 psi. This product is then fed to a tubular reactor with ethylene at 212 F and 300 psi to produce triethyl aluminum. Yields are about 90%. 

Functional diethyl aluminum alkoxides have been prepared by reaction of AlEt3 with an equimolar amount of the corresponding alcohol (XCH2OH). The... 

Moreover, alcohol functionalities have been introduced into the polynor-bornene (PNB) backbone by copolymerization of norbornene with a few percent of 5-acetate norbornene and subsequent acetate reduction. After transformation of the pendant hydroxyl functions into diethyl aluminum alkoxides, sCL has been ring opening polymerized (Scheme 31). Owing to the controlled/ liv-ing character of both polymerization processes the isolated poly(NB- -CL) graft copolymers were characterized by well-defined composition, controlled molecular weight and branching density, and narrow MWD (PDI=1.2-1.4) [92]. 

Tert-Butyl Peracetate Diethyl-aluminum Chloride... 

Tert-Butyl Perbenzoate Diethyl-aluminum Hydride ( )... 

A different type of heterocyclic compound, 1,2-oxazines 201, are accessible from the addition of 1-lithio-l-methoxyallene 183 to isopropylidene glyceraldehyde-derived nitrone 200. The predominant formation of the yw-configurated product 201 (syn anti > 98 2) results. Nevertheless, the stereochemical outcome can be reversed by a precomplexation of the nitrone 200 with diethyl aluminum chloride (equation 79)"". ... 

The polymerization of ethylene in the presence of aluminum chloride is fundamentally changed by the presence of metallic aluminum (Hall and Nash, 72). The product which was obtained at a reaction temperature of 100-200° under superatmospheric pressure was a mobile fuming liquid which was shown to contain diethyl aluminum chloride, a liquid spontaneously inflammable in air. Less conjunct polymerization occurred, the lower-boiling product consisting of olefins mixed with only minor amount of paraffins. 

Tin(II) chloride-Aluminum, 299 Titanium(IV) chloride-Diethyl-aluminum chloride, 309 Titanium(III) chloride-Diisobutyl-aluminum hydride, 303 Titanium(IV) chloride-Lithium aluminum hydride, 310... 

Soluble catalysts, such as diethyl aluminum chloride and ethyl aluminum dichloride, also affect the stereoregularity of the polymer chains. The tendency for the formation of stereoregular polymers is decreased as the size of the alkyl group is increased. Typical structures of these polymers are shown below ... 

Alkylaluminum halides have been investigated as catalysts in the benzalaniline-diazomethane addition.342 Reaction occurs at — 78°C in the presence of diethylaluminum chloride to yield the triazoline adduct diethyl-aluminum iodide, however, leads only to an aziridine. 

The thermal stability of poly(vinyl chloride) is improved greatly by the in situ polymerization of butadiene or by reaction with preformed cis-1,4-polybutadiene using a diethyl-aluminum chloride-cobalt compound catalyst system. The improved thermal stability at 3-10% add-on is manifested by greatly reduced discoloration when the modified poly-(vinyl chloride) is compression molded at 200°C in air in the absence of a stabilizer, hydrogen chloride evolution at 180°C is retarded, and the temperature for the onset of HCl evolution and the peak decomposition temperature (DTA) increase, i.e. 260°-280°C and 290°-325° C, respectively, compared with 240°-260°C and 260°-280°C for the unmodified homopolymer, in the absence of stabilizer. The grafting reaction may be carried out on suspension, emulsion, or bulk polymerized poly(vinyl chloride) with little or no change in the glass transition temperature. 

Butadiene has been converted into poly-l,4-(cis-butadiene) in greater than 98.3% by Ziegler-Natta catalysis comprising neodymium versatate, diethyl aluminum chloride, diisobutylaluminum hydride, and triisobutyMuminum. The polymer was then converted into a polybutadiene-polyurethane copolymer by reacting with a diisocyanate and diol. This copolymer exhibited low cold flow and high affinity for silica or carbon black, excellent elasticity, and abrasion resistance. 

Tris(acetylacetonato)cobalt Diethyl-aluminum Chloride-NORPHOS... 

The hydroalumination of cycloalkenes exhibits two interesting minima in relative rates toward diethyl-aluminum hydride. The half-life (in min) of a 3 1 ratio of Et2AlH and cycloalkene at 78 °C varied thus with ring size C4, 40 C5, 200 Ce, 1880 C7, 110 Cg, 86 C9, 280 Cio, 2500 Cn, 1350. The reactivity of cycloundecene is approximately that of an open-chain internal alkene. The low reactivity of cyclohexene can be ascribed to the eclipsing repulsions generated in the transition state by the syn attack of Et2AlH on the C=C bond (equation 17). ... 

The predominant product in each case was titanium trichloride (aka "tickle 3"), an active catalyst for olefin polymerization. The preferred cocatalyst was diethyl-aluminum chloride (DEAC). TiCl from eq 3.1 contains co-crystallized aluminum trichloride. TiCl from eq 3.3 may contain small amounts of complexed aluminum alkyl. Products from eq 3.1 and 3.2 were supplied commercially by companies such as Stauffer Chemical and Dart (both now defunct). Catalyst from eq 3.3 was manufactured on site by polyolefin producers, usually in an inert hydrocarbon such as hexane. 

Thermal stability of aluminum alkyls is highly dependent upon the ligands bonded to aluminum. For example, triethylaluminum is stable up to about 120 °C (37) and its initial mode of decomposition is by )S-hydride elimination to generate diethyl-aluminum hydride and ethylene (eq 4.20). Diethylaluminum hydride may decompose further to aluminum, hydrogen and two additional equivalents of ethylene (eq 4.21). The overall equation for decomposition is shown in eq 4.22. 

For the synthesis of fra/u-P-cyanohydroxy steroids from the corresponding epoxides treatment with HCN/triethyl aluminum or with diethyl aluminum cyanide proved to be particularly useful. ... 

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