- 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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- 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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- Production of primary and secondary amines by reaction of ammonia with conjugated diene in the presence of Pd/phosphine catalyst and primary or secondary aliphatic alcohol solvent medium
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Short chain, unsaturated primary and secondary amines are prepared by reaction of ammonia and conjugated dienes in a primary or secondary aliphatic alcohol solvent medium and in the presence of a catalyst system comprising a palladium compound co-catalyzed with a phosphine ligand containing 2 to 4 phosphorus atoms.
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