1,721,062 research outputs found
FAB Mass Spectrometric behavior of cyclic hydrido dithio- and dioxycarbene complexes of Pt(II)
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Metal-Catalysis in Oxidation by Peroxides. Sulfide Oxidation and Olefin Epoxidation by Dilute Hydrogen Peroxide Catalyzed by Molybdenum and Tungsten Derivatives under Phase-Transfer Conditions
No full textA procedure is described which allows the oxidation of nucleophilic substrates such as organic sulfides or alkenes, under phase-transfer conditions, by employing dilute hydrogen peroxide, Mo(VI) and W(VI) catalysts, and a neutral lipophilic monodentate ligand as extracting agent. The yields and selectivities observed are generally rather high, thus establishing the synthetic relevance of the method. The success of this procedure, and particularly the efficiency of monodentate ligands, is also discussed from a mechanistic point of view. © 1985, American Chemical Society. All rights reserved
Oxofunctionalization of Non-natural Targets by Dioxiranes. Efficient Oxidation of Buckminsterfullerene C60 with Methyl(trifluoromethyl)dioxirane
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Metal catalysis in oxidation by peroxides. Part 191 1 Part 18: O. Bortolini, V. Conte, F. Di Furia and G. Modena, J. Mol. Catal., 19 (1983) 331.. On the mechanism of rhodium-catalyzed oxidation of terminal olefins to methyl ketones by dioxygen
No full textThe mechanism of the rhodium-catalyzed oxidation of oct-1-ene to octan-2-one by dioxygen in ethanol has been investigated by deuterium labelling studies, employing ethanol-d1 and [2-2H]oct-1-ene respectively. In both sets of experiments, substantial label exchange with the solvent has been observed, suggesting a decomposition pathway for the peroxometallocycle intermediate which does not involve a β-hydride shift. © 1984
Reactions of carbene compounds under FAB conditions : a comparison with the condensed phase behavior
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Massspectrometricbehaviour of some fluorinesubstituted 1,4-estradien-3-oxo steroids
No full textThe selective insertion of a fluorine atom in the molecular skeleton of biologically active compounds often leads to increased selectivity, lower toxicity and dosage, and broad-spectrum activity.
For this reason, the synthesis of four 10-β-fluorine substituted 1,4- estradien-3-oxo derivatives has been carried out and their mass spectrometric behaviour studied, using different ionization techniques, e.g. Fast Atom Bombardment (FAB) and Electron Impact (ED.
What is generally observed with respect to the nonfluorinated analogues is the weakening of C(9)C(10) bond, due to the higher stability of the +C(10)F cation. This reflects a higher abundance of the fragments arising from further cleavage of the C(7)C(8) bond.
Furthermore, for fluorinated compounds an easy H2O loss is observed, showing that in such cases the keto-enol tautomerism is strongly shifted in the enol direction
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