102761-90-0Relevant articles and documents
CHIRAL SYNTHESIS OF ASYMMETRICALLY TETRA-SUBSTITUTED CYCLOPENTANE DERIVATIVES BY DIELS-ALDER ADDITION OF CYCLOPENTADIENE TO UNSATURATED ACYCLIC-SUGAR DERIVATIVES
Horton, Derek,Machinami, Tomoya,Takagi, Yasushi
, p. 135 - 162 (1983)
Optically pure, substituted cyclopentane derivatives of interest in synthesis of prostaglandin analogs have been obtained by stereocontrolled addition of cyclopentadiene to trans α,β-unsaturated sugar derivatives.Methyl (E)-4,5,6,7-tetra-O-acetyl-2,3-dide
Platinum Chloride-Diphosphine-Tin(II) Halide Systems as Active and Selective Hydroformylation Catalysts
Hayashi, Teruyuki,Kawabata, Yasuziro,Isoyama, Toyoshiro,Ogata, Ikuei
, p. 3438 - 3446 (1981)
The hydroformylation of 1-alkenes was efficiently catalyzed by PtCl2-diphosphine-SnX2 systems whose diphosphines were 1,4-bis(diphenylphosphino)butane derivatives with rigid ring skeletons.The effects of the structure of diphosphines, the P/Pt atomic ratio, the sort of tin(II) halide or solvent, the reaction variables, and the structure of olefins on the relative rate and the product distribution were investigated.A higher reaction rate than when using HRh(CO)(PPh3)3, and a linearity of aldehydes up to 99percent, were attained.The coordination structure of the effective diphosphines as well as the reasons for the rate enhancement and for the excellent selectivity were discussed.
CARBONYLATION OF ETHYLENICALLY UNSATURATED COMPOUNDS
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Paragraph 0214, (2016/10/09)
PROBLEM TO BE SOLVED: To provide a process for the carbonylation of ethylenically unsaturated compounds including vinyl esters and a process for the production of 3-hydroxypropanoate esters or 3-hydroxypropanoic acids. SOLUTION: The process comprises reacting the compound with carbon monoxide in the presence of a source of hydroxyl groups and of a catalyst system. The catalyst system is obtainable by combining: (a) a metal of Group 8, 9 or 10 or a compound thereof: and (b) a bidentate ligand of general formula (I): X1(X2)-Q2-A-R-B-Q1-X3(X4). COPYRIGHT: (C)2015,JPOandINPIT
Self-immobilizing precatalysts: Norbornene-bridged zirconium ansa-metallocenes
Polo, Eleonora,Forlini, Fabrizio,Bertolasi, Valerio,Boccia, Antonella Caterina,Sacchi, Maria Carmela
experimental part, p. 1544 - 1556 (2009/07/30)
We report here the synthesis of new tethered biscyclopentadienyl and bisindenyl zirconocenes, bearing one unsaturation on the interannular bridge, and their use as self-immobilizing catalysts. They proved to be active catalysts towards ethylene polymerization in solution, with activities comparable to those displayed by commercial rac-Et-(Ind)2ZrCl2. When tested as self-polymerization catalysts under suitable experimental conditions, they gave colored precipitates that, once reactivated with MAO, were significantly active in ethylene polymerization, although lower than those of the corresponding catalytic systems in solution. The molecular weights of the produced polymers were similar to those obtained with the same catalysts in solution, but their distribution resulted to be broader, with values typical of heterogeneous catalytic systems. From 13C NMR studies we had the first spectroscopic evidence of the actual incorporation of a metallocene of this type into a polymeric chain.
Optical and Neutron Inelastic Scattering Study of 2,3-Dimethylnorbornanes
Brunel, Yvon,Coulombeau, Christian,Coulombeau, Christiane,Jobic, Herve
, p. 2008 - 2015 (2007/10/02)
We have measured the infrared, Raman, and neutron vibrational spectra of the 2,3-dimethylnorbornanes with two CH3 or CD3 groups in the 2- and 3-exo or endo positions.A normal-coordinate analysis has been carried out.No coupling reflecting the strain due to the methyl group appears in the C-CH3 bending and torsional modes of the trans isomer, but appears in the cis-exo isomer (average value 23 cm-1) and in the cis-endo isomer (average value 28 cm-1.The frequencies are used for the determination of the thermodynamic contribution to the standard free energy differences.
Chiral rhodium-diphosphine catalyst capable of catalytic reduction of a tetramisole precursor to give a significant excess of the desired S-(-)isomer, levamisole
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, (2008/06/13)
A soluble, chiral, rhodium-containing catalyst which permits the catalytic reduction of prochiral 3-acyl-1-(2-alkoxyethyl)-4-phenyl-2-imidazolinones to chiral 3-acylimidazolidinones with a substantial excess of the desired S optical isomer. The 3-acylimidazolidinones may in turn be substantially converted to levamisole, and S isomer of tetramisole. The resolution of tetramisole to remove the R isomer is thus avoided.