Hydrogen peroxide with alcohols

In the same spirit DFT studies on peroxo-complexes in titanosilicalite-1 catalyst were performed [3]. This topic was selected since Ti-containing porous silicates exhibited excellent catalytic activities in the oxidation of various organic compounds in the presence of hydrogen peroxide under mild conditions. Catalytic reactions include epoxidation of alkenes, oxidation of alkanes, alcohols, amines, hydroxylation of aromatics, and ammoximation of ketones. The studies comprised detailed analysis of the activated adsorption of hydrogen peroxide with... 

The reaction of hydrogen peroxide with an alcohol in the presence of sulphuric acid gives rise to the corresponding hydroperoxide ... 

Homogeneous mixtures of concentrated peroxide with alcohols or other peroxide-miscible organic liquids are capable of detonation by shock or heat [1]. Furfuryl alcohol ignites in contact with 85% peroxide within 1 s [2], Detonability limits of mixtures with 2-propanol have been measured. Approximately stoichiometric combinations of 50% hydrogen peroxide and the alcohol could be made to detonate, as could a wider range of mixtures with higher test peroxide [3],... 

Ketones play an important role in the decomposition of peroxides to form radicals in alcohols undergoing oxidation. The formed hydroxyhydroperoxide decomposes to form radicals more rapidly than hydrogen peroxide. With an increase in the ketone concentration, there is an increase in the proportion of peroxide in the form of hydroxyhydroperoxide, with the corresponding increase in the rate of formation of radicals. This was proved by the acceptor radical method in the cyclohexanol-cyclohexanone-hydrogen peroxide system [59], The equilibrium constant was found to be K — 0.10 L mol 1 (373 K), 0.11 L mol 1 (383 K), and 0.12 L mol 1 (393 K). The rate constant of free radical generation results in the formation of cyclohexylhydroxy hydroperoxide decomposition and was found to be ki = 2.2 x 104 exp(—67.8/7 7) s 1 [59]. 

According to Fedosyev and Sinyaryev [15] a mixture of 80% hydrogen peroxide with hydrazine hydrate diluted with methyl alcohol in the ratio of 1 1 has the following physico-chemical constants ... 

Exercise 28-12 Irradiation of benzophenone in isopropyl alcohol in the presence of oxygen gives no benzopinacol (the benzophenone is not consumed), but does give 2-propanone (with equal to unity) and hydrogen peroxide (with nearly unity). The reaction does not occur readily in the absence of benzophenone. Explain how benzophenone acts as a photosensitizer for the oxidation of isopropyl alcohol by oxygen. 

Boronatc 6 is oxidized with alkaline hydrogen peroxide to alcohol 24. The corresponding mesylate is reduced with lithium aluminum hydride to a methyl group. 

The reactions of hydrogen peroxide with vanadate have been of interest for many years. Much of the early work was concerned with the function of peroxovanadates as oxygen transfer agents. Alkenes and similar compounds such as allyl alcohols can be hydroxylated or epoxidized. Even alkanes can be hydroxylated, whereas alcohols can be oxidized to aldehydes or ketones and thiols oxidized to sulphones or sulphoxides. Aromatic molecules, including benzene, can be hydroxylated. The rich chemistry associated with the peroxovanadates has, therefore, led to extensive studies of their reaction chemistry. To this end, x-ray diffraction studies have successfully provided details of a number of peroxovanadate structures. 

Several heterogeneous catalysts have been developed for the hydroxylation of alkanes under mild conditions.68,69 One of them is the bi-catalytic system, which combines the ability of palladium to convert hydrogen and oxygen to hydrogen peroxide, with the capability of the iron ions to activate the hydrogen peroxide to hydroxylate hydrocarbons.70 Iron oxide and palladium supported on silica have been used as efficient catalysts for the oxidation of cyclohexane to the alcohol and ketone, via the in situ generation of hydrogen peroxide in an acetone solvent.71... 

Synthesis of secootkiry eokois from l-aOtynes. Dihydroboration at room temperature of a terminal alkyne with either (I) or 9-BBN gives a 1,1-diborylalkane (3) this is treated at 0-5° with I eq. of methyllithium in ether. The product (4) rearranges to (S). An alkyl halide (100 excess) is then added, and the resultant secondary organo-borane (6) is oxidized with alkaline hydrogen peroxide. Secondary alcohols (7) are obtained in 70-85% yield. 

Hydration of attenic nitriles. 4,4-Dialkyl-substitutcd allenic nitriles (1) are converted into allenic amides (2) in 60 70% yield by reaction with hydrogen peroxide in alcoholic sodium hydroxide. 

Blue perchromates, which are referred to the second type, R HjCrO, or R CrOs.HjOa, are formed by the interaction at a low temperature of 30 per cent, hydrogen peroxide with acid solutions of chromates a modified method of preparation consists in the neutralisation of a cooled blue ethereal solution of perchromic acid by an alcoholic solution of the alkali. Similar to the red salts, the crystalline blue perchroniates are unstable in the moist condition they are even more so than the red variety, but both forms may best be preserved by keeping in an atmosphere saturated with aqueous vapour. ... 

Hydrolysis with powdered potassium hydroxide or potassium fluoride on alumina in r-butyl alcohol converts nitriles to amides without further hydrolysis to carboxlic acids. Under similar conditions, addition of alkyl halides gives iV-alkylcarboxyamides. Less drastic acidic or basic hydrolysis conditions involve disproportionation of alkaline hydrogen peroxide with concomitant hydration of the nitrile (equation 21). 

A model system for the synthesis of lignin-like polymers showed that jols would react with the quinone-methlde intermediates in this system by a 1-6 addition (J ). Utilizing this model system, chloroanilines were copolymerized with coniferyl alcohol in the presence of horseradish peroxidase Type II enzyme, hydrogen peroxide, vanillyl alcohol initiator and pH 7.2 buffer (J57). The mechanism of this copolymerization reaction is shown in Equation 36. The... 

Hydrogen peroxide can be used with molybdenum and tungsten catalysts to provide a convenient source of bromine in situ from bromide ion.226 This mimics the action of haloperoxidase enzymes. It provides a less hazardous way to use bromine. Soybean peroxidase can be used with hydrogen peroxide to oxidize alcohols to aldehydes and ketones.227 The use of hydrogen peroxide with an immobilized lipase has allowed the oxidation of linoleic acid to a monoepoxide in 91% yield. The enzyme could be reused 15 times.228 Indole has been oxidized to oxindole in 95% yield using hydrogen peroxide with a chloroperoxi-dase (4.48a).229... 

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