1,721,041 research outputs found
Entrepreneurial culture and the spread of information technology in transport firms. First results on a Southern Italy sample
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Current and Future Trends in the 3PL Industry: Preliminary Results of a Survey on the Italian Sector
No full textEvidence for a charge-transfer intermediate in the catalytic epoxidation of alkenes by ruthenium complexes: a comparison between electrochemical and kinetic data.
No full textCationic Complexes of Rhodium(I) as Catalyst in the Homogeneous O2-oxidation of the Therminal Alkenes to Methyl Ketones
No full textOxidation of C1–C4 alcohols by iron- and ruthenium-sulfophthalocyanine precatalysts with hydrogen peroxide or mono-persulfate in water
No full textA catalytic system consisting of iron- or ruthenium-sulfophthalocyanine and hydrogen peroxide or mono-persulfate was
effective in the oxidation of simple primary and secondary alcohols as well as of simple ketones. The oxidation reactions
were conducted in aqueous media with turnover rates, defined as moles of product per mole of catalyst per minute, up to 5.
Primary alcohols, including methanol, were selectively oxidized into the corresponding carboxylic acids. Secondary alcohols
were transformed into the corresponding ketones, which were found to undergo further oxidation to esters via Baeyer–Villiger
reaction, followed by hydrolysis or alternatively in the case of acetone via direct oxidation to acetic acid and CO2. Moreover,
t-butyl alcohol was also found to be slowly oxidized into acetone and methanol. Analysis of the oxidation reaction of
cyclobutanol indicated an ionic mechanism; no deuterium kinetic isotope effect was measured in the cases of methanol and
ethanol. The mechanistic origin of the catalytic efficiency is also discussed
Direct Synthesis of Adipic Acid by Mono-Persulfate Oxidation of Cyclohexane, Cyclohexanone or Cyclohexanol Catalyzed by Water-Soluble Transition-Metal Complexes
No full textA catalytic system consisting of water-soluble metal sulfophthalocyanines (MPcS) or various ruthenium complexes and mono-persulfate as the oxidant was e.ective in the oxidation of cyclohexanone, cyclohexanol and cyclohexane to adipic acid with di.erent yields and selectivity. Oxidations were conducted at room temperature and under atmospheric pressure in aqueous media (or, in the case of cyclohexane, in a waterÈneat substrate double phase).
The oxidation of cyclohexanol involved step-by-step formation of cyclohexanone, e-caprolactone and
6-hydroxyhexanoic acid, all of which have been identiÐed in the reaction mixtures; in selected cases moderate over-oxidation of adipic acid to glutaric and succinic acid was also observed. Various MPcS catalysts were examined (M\Fe, Co, Ni, Cu and Ru), and the ruthenium derivative exhibited the best performances in terms of rate and selectivity. Mono-persulfate was found to be a more convenient oxidizing reagent than hydrogen peroxide; related patterns were observed when H was used, however extended dismutation of the oxidant limited the 2O2 overall yields. Cyclohexane underwent slow oxidation when reacted with persulfate (waterÈsubstrate double phase) in the presence of the water-soluble metal catalysts ; adipic acid was selectively produced (95%) in the presence of RuPcS catalyst with yields as high as 21% (48 h). The catalytic performance of simpler ruthenium derivatives, such as [RuCl (RuDMS) and (RuPW), was also examined for comparison purposes. A 2(DMSO)4] K5[Ru(H2O)P11O39] kinetic scheme for cyclohexane oxidation is proposed
Dechlorination of chloriphenols with hydrogen peroxide catalyzed by ruthenium (II)-phthalocyanine
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