Hydrogen peroxide benzene oxidation

Scheme 10.12 Oxidation of benzene with hydrogen peroxide.

Titanium-containing zeolite was an efficient catalyst for oxidation of benzene with hydrogen peroxide in a microwave field, affording phenol with high selectivity. It was reported that microwaves had a strong effect on the selectivity of the reaction. 

Wu, J., Karlsson, K. Danielsson, A. (1997) Effects of vitamins E, C and catalase on bromo-benzene- and hydrogen peroxide-induced intracellular oxidation and DNA single-strand breakage in Hep Gi cells. J. Hepatol., 26, 669-677... 

Temperature will affect the degradation rate of different organic pollutants. Weir et al. (1987) reported that benzene and hydrogen peroxide are insensitive to temperature because photochemically induced reactions often have low activation energies. Koubek (1975) stated that temperature has little effect on the oxidation of refractory organics however, Sundstrom et al. (1986) observed that the decomposition rates of some halogenated aliphatics increased with temperature. 

Catalytic activity and selectivity of the mono- and bimetallic mesoporous molecular sieves in oxidation reaction of styrene and benzene with hydrogen peroxide ... 

Yields of phenol from the oxidation of benzene by hydrogen peroxide and... 

Figure 3. Temperature dependencies of the activity for the oxidation of benzene with hydrogen peroxide for 1.5h reaction time. Catalyst, 0.3 mmol H2O, 15 ml CeHe, 10 ml. 10 ml of 0.08 M H2O2 was added dropwise very slowly.

The further oxidation of phenol may also result in the formation of catechol, C,iH4(OH) (1 2). The transformation may be effected by fusion with sodinm hydroxide.85 The snbstance may also be obtained by oxidizing benzene with hydrogen peroxide in the presence of ferrous sulfate88 and by reducing o-benzoquinone with aqueous sulfurous acid in the cold.81 Quinol may be prepared from phenol by oxidation with potassium persulfate in alkaline solution.38 It can also be obtained directly from benzene by the electrolytic oxidation of an alcohol solution to which... 

Iron porphyrins have been studied extensively over the past 30 + years as model systems of cytochrome P450.13 Biomimetic model studies included variants in axial ligands (thiolate and other bases), the oxidation of alkanes, olefins, sulfides, and amines, and utilization of several oxidants such as hypochlorite (bleach), iodoso-benzene (ArlO), hydrogen peroxide, and organic peroxides (ROOH). The first-generation models employed the mevo-tetraary I porphyrins (Figure 3.5). These were... 

A promising and cleaner route was opened by the discovery of titanium silica-lite-1 (TS-1) [1,2]. Its successful application in the hydroxylation of phenol started a surge of studies on related catalysts. Since then, and mostly in recent years, the preparation of several other zeolites, with different transition metals in their lattice and of different structure, has been claimed [3]. Few of them have been tested for the hydroxylation of benzene and substituted benzenes with hydrogen peroxide. Ongoing research on suppoi ted metals and metal oxides has continued simultaneously. As a result, knowledge in the field of aromatic hydroxylation has experienced major advances in recent years. For the sake of simplicity, the subject matter will be ordered according to four classes of catalyst medium-pore titanium zeolites, large-pore titanium zeolites, other transition metal-substituted molecular sieves, and supported metals and mixed oxides. 

Many 3d transition ions were supported on mesoporous silicas by substitution of Si from silica network. The studies have shown a high activity and selectivity of such catalysts in the oxidation of cyclohexene, aromatic hydrocarbons, phenols, and alcohols. Thus, V, Ti, Cr, Mn, Fe, Ni, and Co incorporated into MCM-41 materials showed activity in liquid-phase oxidation of styrene and benzene with hydrogen peroxide [15,29,79]. The best activity in the oxidation of benzene was obtained for Ti-MCM-41, while for the oxidation of styrene the most active were Cr-MCM-41 and CrNi-MCM-41. The activity of these catalysts decreased with an increase of the number of 3d electrons of the metal ions. Ti,... 

Preliminary economic evaluations suggest that direct oxidation of benzene by hydrogen peroxide is not yet competitive compared with the traditional cumene process, particularly if the acetone recycling is taken into account, but also that it could become profitable should the acetone price fall close to its fuel value. 

Forced-flow polymeric membrane reactors have also been successfully tested for the oxidation of benzene to phenol by Molinari and co-workers. Mixed-matrix membranes consisting of CuO powder or CuO nanoparti-cles dispersed in PVDF were prepared by the inversion phase method, by using dimethylacetamide (DMAc), dimethylformamide (DMF) or N-methyl-2-pyrrolidone (NMP) as solvents and water as non-solvent. The membranes were assembled in a ultraliltration unit to which a solution of acetonitrile/benzene and hydrogen peroxide (HjOj) was fed. The best results were obtained with a PVDF membrane hlled with CuO nanoparticles, with a phenol yield of 2.3% at 35°C and a contact time of 19.4 s in a single pass, in the presence of ascorbic acid. 

Tetracyanoethylene oxide [3189-43-3] (8), oxiranetetracarbonitnle, is the most notable member of the class of oxacyanocarbons (57). It is made by treating TCNE with hydrogen peroxide in acetonitrile. In reactions unprecedented for olefin oxides, it adds to olefins to form 2,2,5,5-tetracyanotetrahydrofuran [3041-31-4] in the case of ethylene, acetylenes, and aromatic hydrocarbons via cleavage of the ring C—C bond. The benzene adduct (9) is 3t ,7t -dihydro-l,l,3,3-phthalantetracarbonitrile [3041-36-9], C22HgN O. 

Methylpyridine-l-oxide has been prepared by the oxidation of 3-methylpyridine with hydrogen peroxide in glacial acetic acid, with 40% peracetic acid and sodium acetate, and with per benzoic acid in benzene. ... 

A heterocyclic ring may be used in place of one of the benzene rings without loss of biologic activity. The first step in the synthesis of such an agent starts by Friedel-Crafts-like acylation rather than displacement. Thus, reaction of sulfenyl chloride, 222, with 2-aminothiazole (223) in the presence of acetic anhydride affords the sulfide, 224. The amine is then protected as the amide (225). Oxidation with hydrogen peroxide leads to the corresponding sulfone (226) hydrolysis followed by reduction of the nitro group then affords thiazosulfone (227). ... 

Benzocyclobutene-l,2-dione (11) can be condensed with benzene-1.2-diamine to provide an annulated quinoxaline (cf. Houben-Weyl, Vol. E9b/Part 2, p203), which on oxidation with hydrogen peroxide in acetic acid leads to the 1,4-diazocine derivative 12.34... 

Asymmetric epoxidation of olefins with ruthenium catalysts based either on chiral porphyrins or on pyridine-2,6-bisoxazoline (pybox) ligands has been reported (Scheme 6.21). Berkessel et al. reported that catalysts 27 and 28 were efficient catalysts for the enantioselective epoxidation of aryl-substituted olefins (Table 6.10) [139]. Enantioselectivities of up to 83% were obtained in the epoxidation of 1,2-dihydronaphthalene with catalyst 28 and 2,6-DCPNO. Simple olefins such as oct-l-ene reacted poorly and gave epoxides with low enantioselectivity. The use of pybox ligands in ruthenium-catalyzed asymmetric epoxidations was first reported by Nishiyama et al., who used catalyst 30 in combination with iodosyl benzene, bisacetoxyiodo benzene [PhI(OAc)2], or TBHP for the oxidation of trons-stilbene [140], In their best result, with PhI(OAc)2 as oxidant, they obtained trons-stilbene oxide in 80% yield and with 63% ee. More recently, Beller and coworkers have reexamined this catalytic system, finding that asymmetric epoxidations could be perfonned with ruthenium catalysts 29 and 30 and 30% aqueous hydrogen peroxide (Table 6.11) [141]. Development of the pybox ligand provided ruthenium complex 31, which turned out to be the most efficient catalyst for asymmetric... 

Epoxyeyclohexanone has been prepared in 30% yield4 by epoxi-dation of 2-cyclohexen-l-one with alkaline hydrogen peroxide, using a procedure described for isophorone oxide (4,4,6-trimethyl-7-oxabicyclo[4.1.0]heptan-2-one).5 A better yield (66%) was obtained using f r/-butyl hydroperoxide (1,1-dimethylethylhydroperoxide) and Triton B in benzene solution.6 The procedure described here is simple and rapid. 

Catalysts were prepared with 0.5, 1.0, 2.0 and 5.0 wt% of iron loaded on activated carbon. Benzene hydroxylation with hydrogen peroxide as oxidant was carried out. The conversion of benzene, selectivity and yield of phenol for these catalysts are shown in Fig. 4. As the weight of loaded metal increased the benzene conversion increased by about 33% but the selectivity to phenol decreased. The yield of phenol that was obtained with S.OFe/AC was about 16%. 

The preparation of iron impregnated activated carbon as catalysts and the catalytic performance of these catalysts were studied in benzene hydroxylation with hydrogen peroxide as oxidant. 5.0Fe/AC catalyst containing 5.0 wt% iron on activated carbon yielded about 16% phenol. The addition of Sn on 5.0Fe/AC catalyst led to the enhancement of selectivity towards phenol. 

The transformation of isoquinoline has been studied both under photochemical conditions with hydrogen peroxide, and in the dark with hydroxyl radicals (Beitz et al. 1998). The former resulted in fission of the pyridine ring with the formation of phthalic dialdehyde and phthalimide, whereas the major product from the latter reaction involved oxidation of the benzene ring with formation of the isoquinoline-5,8-quinone and a hydroxylated quinone. 

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