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Sintesi di dimetil acetali, dietil acetali e acetali ciclici catalizzata da amminopropil-silice HCl (APS HCl).
No full textSintesi di solfossidi mediante ossidazione di tioeteri con acido nitrico catalizzata da Au(III) in condizioni di trasferimento di fase
No full textA biphasic process for the oxidation of sulfides: a new convenient route to sulfoxides
No full textA biphasic (nitromethane/water) process is provided for the oxidation of alkyl- and ary l-sulf ides by aqueous nitric and sulfuric acids (20% each). This represents a preparatively useful and convenient route to sulfoxides
Preparazione di isossazoli e 2-isossazoline per ossidazione di alchini terminali con acido nitrico, catalizzate da Au(III) in ambiente bifasico
No full textA general procedure for the selective oxidation of sulfides to sulfoxides by nitric acid: tetrabromoaurate(III) catalyst in a biphasic system
No full textTetrabromoaurate(III) is an efficient catalyst for the oxidn. of sulfides to sulfoxides by nitric acid in a biphasic system (nitromethane/water). The system is selective and can be applied to the oxidn. of any type of dialkyl and alkyl aryl sulfides and also of diaryl sulfides activated by electron-releasing substituents. The nature of the active species has been investigated in relation to the mechanistic aspects
Phase transfer catalysis of Gold(III) chloride in the oxidation of thioethers to sulfoxides by nitric acid
No full textSelective and regiospecific oxidation of dithiaalkanes in a gold(III) catalyzed phase-transfer process
No full textThe oxidation of dithiaalkanes has been carried on in a gold(III) catalyzed phase-transfer process. Using a higher concentration of catalyst and oxidant (procedure A) the bis(benzylthio)alkanes Bz-S-(CH2)-S-Bz (Bz = benzyl) were .Oxidized to the corresponding monosulfoxide when n = 1 and to disulfoxide [bis(benzylsulfinyl)alkanes] when n = 2, 3, 4, 5, and 8. In more diluite conditions (procedure B) high yields of monosulfoxides were obtained also in the case of n = .2 and 3 while the selectivity decreased for n = 4, 5, and 8. The oxidation of asymmetric dithiaalkanes, R-S-(CH2)3-S-R' (RR' = BzPh, BzCy, CyPh; Ph = phenyl, Cy = cyclohexyl), under experimental conditions B was regiospecific leading either to the formation of only one type of monosulfoxide (RR' = BzPh) or to the formation of both types of monosulfoxides but in different yield (RR' = BzCy and CyPh); in all cases the alkylic and less hindered sulfur atom was oxidized in preference
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