Reaction Of Triethylaluminum Research Articles

Reactions of acyl phosphonates with organoaluminum reagents: a new method for the synthesis of secondary and tertiary α-hydroxy phosphonates

The reactions of organoaluminum reagents (trimethylaluminum, triethylaluminum, etc.) with aryl and alkyl acyl phosphonates, which lead to the formation of α-hydroxy phosphonates in moderate to good yields, are reported. This method provides easy access to secondary and tertiary α-hydroxy phosphonates depending on the reaction conditions. The reactions of triethylaluminum with a series of acyl phosphonates at 0 °C gave the secondary α-hydroxy phosphonates, while at −100 °C they afford the tertiary α-hydroxy phosphonates.

Syndiospecific Polymerization of Styrene Using Half-Titanocene Catalyst Covalently Supported on MgCl2/AlEtn(OEt)3-n

The novel half-titanocene catalyst bearing reactive functional amino group, η5-pentamethylcyclopentadienyltri(p-amino-phenoxyl) titanium [Cp∗Ti(p-OC6H4NH2)3], was easily synthesized by the reaction of η5-pentamethylcyclopentadienyltrichloride titanium (Cp∗TiCl3) with p-amino phenol in the presence of triethyl amine (NEt3). Cp∗Ti(p-OC6H4NH2)3 covalently anchored on MgCl2/AlEtn(OEt)3-n support obtained from the reaction of triethylaluminium (AlEt3) with the adduct of magnesium chloride (MgCl2) and ethanol (EtOH), has been investigated and used to catalyze syndiospecific polymerization of styrene. Influences of the support structure, cocatalyst, and the molar ratio of Al in methylaluminoxane (MAO) and Ti (AlMAO/Ti) on catalytic activity, syndiotacticity and molecular weight of the resultant polystyrene were investigated. Compared with the corresponding Cp∗Ti(p-OC6H4NH2)3 homogeneous catalyst, a considerable increase in activity and molecular weight of syndiotactic polystyrene (sPS) was observed for the Cp∗Ti(p-OC6H4NH2)3-MgCl2/AlEtn(OEt)3-n supported catalyst even at a relatively low AlMAO/Ti ratio of 50, and the kinetics of polymerization was stable during the reaction process.

β-Diketiminate aluminium complexes: synthesis, characterization and ring-opening polymerization of cyclic esters

A series of aluminium alkyl complexes (BDI)AlEt(2) (3a-m) bearing symmetrical or unsymmetrical beta-diketiminate ligand (BDI) frameworks were obtained from the reaction of triethyl aluminium and the corresponding beta-diketimine. The monomeric structure of the aluminium complex 3k was confirmed by an X-ray diffraction study, which shows that the aluminium center is coordinated by both of the nitrogen donors of the chelating diketiminate ligand and the two ethyl groups in a distorted tetrahedral geometry. Attempt to synthesize beta-diketiminate aluminium alkoxide complexes by the reactions of monochloride complex "(BDI-2a)AlMeCl" (4) with alkali salts of 2-propanol gave unexpectedly an aluminoxane [(BDI-2a)AlMe](2)(micro-O) (7) as characterized by X-ray diffraction methods. Complexes 3a-m and [(2,6-(i)Pr(2)C(6)H(3)NCMe)(2)HC]AlEt(2) (8) were found to catalyze the ring-opening polymerization (ROP) of epsilon-caprolactone with moderate activities. The steric and electronic characteristics of the ancillary ligands have a significant influence on the polymerization performance of the corresponding aluminium complexes. The introduction of electron-donating substituents at the para-positions of the aryl rings in the ligand resulted in an apparent decrease in catalytic activity. Complex 3h showed the highest activity among the investigated aluminium complexes due to the high electrophilicity of the metal center induced by the meta-trifluoromethyl substituents on the aryl rings. The increase of steric hindrance of the ligand by introducing ortho-substituents onto the phenyl moieties also resulted in a decrease in the catalytic activity. Although the viscosity average molecular weights (M(eta)) of the obtained poly(caprolactone)s increased with the enhancement of monomer conversion, the ROPs of epsilon-caprolactone initiated by complexes 3a-m and 8 were not well-controlled, as judged from the broad molecular weight distributions (PDI = 1.66-3.74, M(w)/M(n)) of the obtained polymers and the nonlinear relationship of molecular weight versus monomer conversion.

Reactivity of triethylaluminum with a series of secondary amines.: Adduct and aminoalane dimer synthesis and characterization; the crystal structures of [Et 2AlN( c-C 6H 11) 2] 2 and [Et 2AlNC 4H 8NCH 3] 2

The reactions of triethylaluminum with a series of 13 secondary amines (RH=HNMe 2, HNEt 2, HNPr 2 n, HNPr 2 i, HNBu 2 n, HNBu 2 i, HNBu 2 s, HNC 4H 8, HNC 5H 10, HNC 6H 12, HN( c-C 6H 11) 2, HN(CH 2Ph) 2, and HNC 4H 8NMe) afford room-temperature stable, clear, colorless liquid complexes. These complexes were characterized by 1H and 13C NMR, IR and elemental analyses. Trends in the NMR chemical shift data are compared with data previously reported for the analogous trimethylaluminum, -gallium, and -indium compounds in terms of the steric properties of the amines. Subsequent thermolysis of these complexes yields dimeric aminoalanes via 1,2-elimination of ethane in all cases. The dimers were characterized by 1H and 13C NMR, IR, melting point, cryoscopic molecular weight determinations, and elemental analyses. The NMR chemical shift data are compared with known data for the [Me 2AlR] 2 and [Me 2GaR] 2 series. The molecular structures of [Et 2AlN( c-C 6H 11) 2] 2 and [Et 2AlNC 4H 8NCH 3] 2, obtained from X-ray crystal data, are presented and discussed in terms of the correlations between the structural parameters of the Al 2N 2 ring and the nature of the Al and N substituents.

Chemically induced dynamic nuclei polarization and free radicals in the reaction of triethylaluminum with nitrobenzene

The reaction of triethylaluminum with nitrobenzene in hydrocarbon solvents was studied by GC-MS and CIDNP techniques. Radical intermediates participating in a complex process of reduction and alkylation of nitrobenzene were observed in the reaction products (nitrobenzene radical anion, ethyl radical, and nitroxyl radical), and routes of their formation and decay were discussed.

The First Organoaluminum Derivative of a Hydroxy Carboxylic Acid. Molecular Structure of the Tetranuclear [Et2Al]4[(μ-O2C)C6H4-2-μ-O]2 Adduct

The reaction of triethylaluminum with salicylic acid in a 2:1 molar ratio results in the formation of the novel tetranuclear diethylaluminum aryloxide carboxylate adduct [Et2Al]4[(μ-O2C)C6H4-2-μ-O]2 (1). Compound 1 has been characterized by elemental analysis and 1H and 27Al NMR and IR spectroscopy, and its molecular structure has been determined by X-ray crystallography. The molecule is a centrosymmetric cluster with a skeleton framework consisting of three fused heterocycle rings, one 12- and two 6-membered. The two diethylaluminum units symmetrically join the two salicylic acid dianions by the formation of bridges between the aryloxide oxygen atom and one carboxylate oxygen atom of the second ligand. The two other diethylaluminum units are chelated by the aryloxide and second carboxylate oxygen atoms of each ligand. The carboxylate groups display a bidentate coordination mode with syn−anti conformation. The binding mode of the carboxylate and alkoxide ligands to metal centers is also discussed.

Synthesis, structure, and pyrolysis of organoaluminum amides derived from the reactions of trialkylaluminum compounds with ethylenediamine in a 3:2 ratio

The reactions of triethylaluminum and trimethylaluminum with ethylenediamine have been studied. Heating of the initially formed (R 3 Al) 2 •en and R 3 Al•en adduct mixture results in the formation of RAl[(HN(CH 2 ) 2 NH)AlR 2 ] 2 (R=CH 3 , and C 2 H 5 ). The structures and formation mechanisms of these two compounds, as well as their pyrolysis reactions, have been studied with 1 H, 13 C, and 27 Al NMR, FTIR, MS, GC, DSC, and TGA techniques. The methyl derivative was characterized by a single-crystal X-ray diffraction analysis: space group P2/c

Reaction of Triethylaluminum with Bis(Diphenylphosphinoyl)Methane. Synthesis and Molecular Structure of [Al(C2H5)][(Ph2P(O))2C]2[Al(C2H5)2]2

Abstract Reaction of triethylaluminum with bis(diphenylphosphinoyl)methane in toluene/heptane affords the crystalline condensation product [Al(C2H5)][(Ph2P(O))2C]2[Al(C2H5)2]2. The title compound crystallizes in the monoclinic space group C2/c with unit cell parameters a = 26.157(9), b= 10.261(3), c = 24.607(9) A, β = 120.48(2)[ddot], V = 5691.65 A3 and ρ = 1.23 g cm−3 for Z = 4. Full-matrix least-squares refinement based on 2778 observed reflections converged at R = 0.051, R w = 0.068. During the course of the reaction both of the central methylene C-H bonds of each ligand were cleaved, along with four Al-Et bonds, thereby eliminating four units of ethane, and resulting in a five-coordinate aluminum atom residing in a trigonal bipyramidal environment at the core of the molecule.

Chemical polarization of nuclei in the reaction of triethyl- and triisobutylaluminum with hexachlorocyclopentadiene

The radical character of the reaction of triethylaluminum and triisobutylaluminum with hexachlorocyclopentadiene was demonstrated by the method of chemical polarization of nuclei and the scheme of the reaction was proposed.

Investigation of AlC bond reactivity in a bidentate ligand system: structure and reactivity studies of [Al(8-quinolinol)(C 2H 5) 2] 2

The reaction of triethyl aluminum, Al 2(C 2H 5) 6 with 8-quinolinol yields the dimeric dialkyl aluminum complex [Al(8-quinolinol)(C 2H 5) 2] 2. The X-ray crystal structure, monoclinic, P2 1/ c, a=18.132(3), b=9.784(5), c=15.191(2) Å, β=112.06(1)°, V= 2497.6(22) Å 3, Z=4, shows that the complex dimerizes through the oxygen atoms, forming a four membered ▪ ring. The 8-quinolinol moiety functions as a bidentate ligand and the coordination environment about the aluminum center is a distorted trigonal-bipyramid. The 1H NMR spectrum indicates that the complex undergoes a conformational rearrangement in solution, removing the equivalence of the alkyl protons. This complex is reactive in both the solid state and solution to air and moisture.

Triethylaluminum-Based Ferrocenylalanes. Synthesis and Crystal Structure of (η5−C5H5)Fe[η5−C5H4Al2(C2H5)4Cl

Abstract The trietheylaluminum based ferrocenylalane (η5−C5H5)Fe[η5−C5H4Al2(C2H5)4Cl] was prepared from the reaction of triethylaluminum with chloromercuriferrocene in toluene and characterized by single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P 1 with unit cell dimensions a = 9.353(3) A, b = 10.281(7) A, c = 11.599(9) A, α = 79.64(7)°, β = 69.41(6)°, γ = 84.33(4)°, and Z = 2 for Dc = 1.27 g cm−3. Full-matrix least-squares refinement has led to a final R factor of 0.068 based on 1866 independent observed reflections. The two diethylaluminum units are bridged by a chlorine atom and one carbon atom of a cyclopentadienyl group, thus forming an Al-Cl-Al-C ring. The four-membered ring is planar to within 0.02 A. The Al-Cl distances are 2.404(4) A and 2.266(5) A. The Al-Cl-Al angle is 78.9(1)° while the Al-C-Al angle is 91.3(4)°. No significant aluminum-iron interaction is observed (Al… Fe = 3.137(4) A).

ChemInform Abstract: Reactions of Organo‐Aluminum Compounds with Peresters.

AbstractThe reaction of triethyl aluminum (Ia) with the peresters (II) gives the intermediates (III) ‐ (VI), according to the reaction products formed after hydrolysis and the ESR data obtained in the presence of 2‐methyl‐2‐nitrosopropane.

Reaction of 2,7-dialkyl- and 1,2.7-trialkyldecahydro-4-quinolones with triethylaluminum

The reaction of triethylaluminum with stereoisomeric 2,7-dimethyl- and 1,2,7-trimethyldecahydro-4-quinolones and their 7-tert-butyl-substituted analogs was studied. The reaction of triethylaluminum with ketones that have an equatorial 2-CH3 group proceeds in two directions — reduction of the carbonyl group to an alcohol group and alkylation to give tertiary 4-ethyl-substituted alcohols — in benzene. depending on the reagent ratio. The stereochemistry of the reduction of the carbonyl group depends on the temperature. Only an alkylation product is formed in tetrahydrofuran (THF) and diethyl ether. The reaction of triethylaluminum with ketones that have an axial 2-CH3 group depends on the nature of the solvent. Epimeric secondary alcohols are formed in toluene at various ratios of the reacting substances, whereas tertiary ethyl-substituted alcohols are formed in THF and diethyl ether.

Further Studies in the Reactions of Triethylaluminum with Bis-(diphenylphosphino) amines

Triethylaluminum reacts with bis(diphenylphosphino)-n-propylamine and bis(diphenylphosphino)-n-butylamine to form the 1:1 adducts in which the aluminum atom is pentacoordinate. Triethylaluminum does not react with other bis(diphenylphosphino)amines in which the third substituent on the nitrogen atom is α-methylbenzyl, benzyl, or 1,1-dimethylamine. The formation of adducts from straight-chain hydrocarbons and the total lack of reactivity for the Lewis bases containing bulky groups leads to the postulation that steric hindrance prevents the free pair of electrons on the phosphorus atoms from being available to the triethylaluminum.

Kinetics and mechanism of the reactions of triethylaluminium with phenylacetylene

The kinetics of the reactions between triethylaluminium and phenylacetylene have been studied in cyclohexane between 313 and 333 K. Two reactions are observed; metallation, which proceeds by the bimolecular reaction of dimeric triethylaluminium and phenylacetylene with a rate coefficient k2= 106.8 ± 1.5 e–(64000 ± 2900K/8.314T) dm3 mol–1 s–1, and addition which proceeds by way of an alkyne π-complex (I). The equilibrium constant for the formation of (I) has been estimated. The rate controlling step of the addition reaction is a rearrangement of (I), through a four-centre transition state, with a rate coefficient k1= 1011.6 ± 0.9 e–(94000 ± 2500K)/8.314T) s–1.

Influence d'halogénures d'ammonium quaternaire sur la réaction entre le triéthylaluminium et le benzaldéhyde

Tetrabutylammonium halides enhance the addition/reduction ratio in the reaction of triethylaluminium with benzaldehyde in ether, and simultaneously lower the reactivity of the organoaluminium compound. These effects, which increase in the order I ⪡t Br ⪡ Cl, are interpreted as resulting from the existence of the complexes Bu 4 NX· Et 3 Al and Bu 4 NX· 2 Et 3 Al.

Reaction of triethylsilanethiol and related compounds with triethylaluminum

The reaction of triethylaluminum with compounds of the (C2H5)3SiXH series (X=S, Se, Te) proceeds with a stepwise replacement of the ethyl groups by (C2H5)3SiX moieties. Depending on the ratio of the reactants, it is possible to obtain either the monosubstitution products (C2H5)3SiXAl(C2H5)2, or the disubstitution products [(C2H5)3SiX]2AlC2H5. The disproportionation reactions of these products were investigated.

Reactions and complex formation between triethyl-aluminium and methyl methacrylate

The reaction of triethylaluminium and methyl methacrylate (MMA) was followed at room temperature in sealed NMR tubes. Hydrolysed reaction products were also analysed. Ethylation of MMA occurs only when MMA/A1 < 1.0. At higher ratios a strong, unreactive 1 1 complex prevails. Evidence presented suggests that a second 1 2 complex is responsible for the reactions at lower ratios. The normal reaction is carbonyl addition: twofold carbonyl adducts of the type: CH 2CMeCEt 2OAl, forming rapidly. Subsequent changes appear to involve only slow exchange or association of these ethylaluminium alkoxides. Reduction of the carbonyl group occurs to a minor and irreproducible extent. There is no evidence for 1 4 attack on MMA.

The reaction of triethylaluminum with epoxides

Triethylaluminum and 1,1-dialkylethylene oxides yield as major products (after hydrolyses) substituted neopentyl alcohols. Triethylaluminum and propylene oxide react (mole ratio >1) forming 2-methylbutanol in high (ca. 98%) yield. The products of this reaction are dependent on the mole ratio of reactants. When the ratio (triethylaluminum/propylene oxide) is 0.7, 2-pentanol is the major product.The products of reaction with cis- and trans-2,3-epoxybutane (mole ratio triethylaluminum/epoxide >1) were threo-3-methyl-2-pentanol and erythro-3-methyl-2-pentanol respectively indicating inversion had occurred at the carbon receiving the ethyl group. Mechanisms for these reactions are discussed.

Reactions of triethylaluminum with some hydrazinophosphorus compounds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of triethylaluminum with some hydrazinophosphorus compoundsStanley F. Spangenberg and Harry H. SislerCite this: Inorg. Chem. 1969, 8, 4, 1004–1006Publication Date (Print):April 1, 1969Publication History Published online1 May 2002Published inissue 1 April 1969https://doi.org/10.1021/ic50074a060RIGHTS & PERMISSIONSArticle Views72Altmetric-Citations23LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (450 KB) Get e-Alerts Get e-Alerts