- The synthesis and deep purification of GaEt3. Reversible complexation of adducts MAlk3 (M = Al, Ga, In; Alk = Me, Et) with phenylphosphines
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Optimal parameters of organomagnesium technique of synthesis of triethylgallium have been defined. Various techniques of deep purification of triethylgallium to the extent required in metalorganic vapor-phase epitaxy MOVPE have been studied: by way of residue ether displacement through high-performance rectification and interaction with high pure aluminum and gallium trichloride, and by way of reversible complexation with triphenylphosphine, 1,3-bis(diphenylphosphine)propane and 1,5- bis(diphenylphosphine)pentane. Advantages and disadvantages of each technique have been identified. We have shown high performance of adduct purification technique covering trimethyl and triethyl derivatives of aluminum, gallium and indium. The structure of donor-acceptor complexes between metal alkyls and the above-mentioned phosphines have been verified using H and 31P NMR spectroscopy and X-ray studies, as well as quantum chemical calculations. Thermal stability of triethylgallium and oxidation of its adducts with phosphines have been studied.
- Shatunov,Korlyukov,Lebedev,Sheludyakov,Kozyrkin,Orlov, V.Yu.
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experimental part
p. 2238 - 2251
(2011/06/22)
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- A mild and efficient CsOH-promoted synthesis of ditertiary phosphines
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A mild and efficient method for the synthesis of ditertiary phosphines has been developed. In the presence of cesium hydroxide, molecular sieves, and DMF, various dihalides were coupled with diphenylphosphine at room temperature, and the results have demonstrated that this methodology offers a general synthetic procedure producing a variety of ditertiary phosphines in high yields.
- Honaker, Matthew T.,Salvatore, Ralph Nicholas
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p. 277 - 283
(2007/10/03)
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- CsOH-promoted P-alkylation: A convenient and highly efficient synthesis of tertiary phosphines
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A mild and efficient method for the synthesis of tertiary phosphines and ditertiary phosphines has been developed. In the presence of cesium hydroxide, molecular sieves and DMF at room temperature, various secondary phosphines and alkyl bromides were examined, and the results have demonstrated that this methodology offers a general synthetic procedure to produce tertiary phosphines in moderate to high yields. Optically active tertiary phosphine synthesis is also described.
- Honaker, Matthew T.,Sandefur, Benjamin J.,Hargett, James L.,McDaniel, Alicia L.,Salvatore, Ralph Nicholas
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p. 8373 - 7377
(2007/10/03)
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- Preparation of organohalosilanes
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When oganohalosilanes are prepared by charging a reactor with a contact mass containing a metallic silicon powder and a copper catalyst, and introducing an organohalide-containing gas into the reactor to effect the direct reaction, a poly(organo)phosphino compound is added to the contact mass. The invention is successful in producing organohalosilanes at a significantly improved production rate without reducing the selectivity of useful silane.
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- Process for the preparation of substituted phenols
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A process for the preparation of substituted phenols, in particular, the condensation of phenols having one or more alkyl substituents with a butadiene derivative comprising at least six carbon atoms, in particular myrcene and/or β-springene is disclosed. The cyclization, in the form of chromans, of the products obtained during this condensation and their hydrogenation in order to prepare vitamin E is also disclosed.
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- Radical Cations of Bis(diphenylphosphino) Derivatives (Ph2P-R-PPh2): The Formation of Localized, Cyclic, and Dimeric Configurations. An ESR and Quantum Chemical Study
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A matrix ESR study on radiogenic radical cations of Ph2P-R-PPh2 derivatives with various linkers (R) is presented.The experiments show that in a frozen dichloromethane solution the radical cations can adopt localized (Ph2PR*+), cyclic , and dimeric (Ph2RP*-PRPh2+) configurations, depending on the nature of the linker.The cyclic and dimeric products are formed in the reaction of a localized cation with a second free-electron pair, resulting in an intra- or intermolecular three-electron P-P ?* bond, respectively.The formation of the cyclic structure, with a strongly bent P-P ?* bond, requires a specific proximate position of the two phosphine moieties in the precursor molecule.The mutual orientation of the two free-electron pairs of the precursors is assessed by NMR via the nJPP spin-spin coupling constant.Ab initio UHF quantum chemical calculations at the 3-21G*/SCF level support the assignments.
- Janssen, Rene A. J.,Aagaard, Olav M.,Cabbolet, Marcoen J. T. F.,Waal, Bas F. M. de
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p. 9256 - 9263
(2007/10/02)
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- Process for the selective preparation of alkenecarboxylic acid derivatives
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A process for the selective carbonylation of a conjugated diene by contacting with carbon monoxide in the presence of a hydroxyl-group-containing compound such as water, alcohol, phenol or carboxylic acid in liquid phase using a catalyst system formed by the combination of: (a) a palladium compound and (b) at least one organic bidentate phosphine.
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- Preparation of biaryl compounds
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A method for the preparation of biaryl compounds is disclosed which comprises contacting an aromatic halide in the presence of a catalyst comprising zerovalent nickel, a bidentate phosphorus-containing coordinating ligand and a reducing metal in a polar, aprotic solvent system for a time and under conditions suitable for the formation of biaryl compound.
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