Phenanthrene catalytic oxidation

In Europe, where an abundant supply of anthracene has usually been available, the preferred method for the manufacture of anthraquinone has been, and stiU is, the catalytic oxidation of anthracene. The main problem has been that of obtaining anthracene, C H q, practically free of such contaminants as carbazole and phenanthrene. Many processes have been developed for the purification of anthracene. Generally these foUow the scheme of taking the cmde anthracene oil, redistilling, and recrystaUizing it from a variety of solvents, such as pyridine (22). The purest anthracene may be obtained by azeotropic distillation with ethylene glycol (23). 

Os04 will add to C=C bonds but will only attack the most reactive aromatic bonds thus benzene is inert, but it will attack the 9,10 bond in phenanthrene and will convert anthracene to 1,2,3,4-tetrahydroxytetra-hydroanthracene. It can be used catalytically in the presence of oxidizing agents such as NaC103 or H2O2 [53],... 

Hemoglobin is another heme-containing protein, which has been shown to be active towards PAH, oxidation in presence of peroxide [420], This protein was also modified via PEG and methyl esterification to obtain a more hydrophobic protein with altered activity and substrate specificity. The modified protein had four times the catalytic efficiency than that of the unmodified protein for pyrene oxidation. Several PAHs were also oxidized including acenaphthene, anthracene, azulene, benzo(a)pyrene, fluoranthene, fluorene, and phenanthrene however, no reaction was observed with chrysene and biphenyl. Modification of hemoglobin with p-nitrophenol and p-aminophenol has also been reported [425], The modification was reported to enhance the substrate affinity up to 30 times. Additionally, the solvent concentration at which the enzyme showed maximum activity was also higher. Both the effects were attributed to the increase in hydrophobicity of the active site. 

Tetramethoxy aristolochic acid (80) was obtained by nitration from the corresponding 3,4,6,7-tetramethoxy-phenanthrene-l-carboxylic acid (81), which was obtained from glaucine (82) via exhaustive Hofmann degradation (twice) followed by oxidation. Catalytic hydrogenation with Pd-C afforded the relevant aristolactam (83) (Scheme 10) (82). 

Included in this section are oxidations of benzene and phenyl rings, and in general the oxidation of aromatic and polycyclic aromatic compounds. The main catalyst for this type of reaction is RuO. The earliest example was the use of stoich. RuOy CCI4 for phenanthrene oxidation [239], while the first catalytic reagent was RuO / aq. Na(I04)/acetone for oxidation of pyrene [240]. Another early example was the conversion of diketo compounds to the nor-diketo acids, with concomitant destruction of the two phenyl rings by RuO /aq. NallO l/acetone (Fig. 3.18, 3.2.2.1) [206]. 

Olefins, see also Catalytic method (p. 989). Djerassi and Engle report one experiment on the oxidation of phenanthrene with ruthenium tetroxide in carbon tetrachloride the reaction mixture contained considerable starting material and a small amount of phenanthrenequinone. Berkowitz and Rylander oxidized cyclohexene in the same way and obtained adipaldehyde in low yield as the only isolated product they regard the method as unsatisfactory for the production of aldehydes and acids because these substances are strongly adsorbed on the ruthenium dioxide formed. 

The trans-dihydrophenanthrenes formed by stilbene photo-cyclisation are thermally unstable and revert to the stilbene unless an oxidant is present, in which case the phenanthrene is produced. In order to ensure that oxidation occurs the reaction is commonly conducted under aerated conditions in the presence of a catalytic quantity of iodine. However, it has been reported that the yields of the phenanthrene can be increased if a stoichiometric quantity of iodine and propylene oxide in the absence of air is used. ... 

The frazzs-4a,4 -dihydrophenanthrene (lb) intermediates have to be removed from the equilibrium by aromatization to the corresponding phenanthrenes (e. g. 2) either by cleavage of a suitable leaving group at the 4 a-position in 1 b or, most commonly, by an oxidation agent the generally accepted method employs the use of air plus a catalytic amount of iodine. This procedure has been applied as a key step in numerous syntheses of interesting PAHs, such as helicenes [70] as well as the first syntheses of [7]phenacene (34, [71]) and [7]circulene (17, [72]) respectively (see Scheme 5,13). 

The past year has seen the publication of Comprehensive Organic Chemistry, one volume of which contains much information on the six-membered ring systems to be reviewed in this article a monograph on the chemistry of condensed pyrazines has also appeared. Reviews on 1,4-thiazines, l,3-benzothiazines," pyridazines, benzo[c]cinnolines, quinazolines, purines, pyrrolo[3,2-c]quino-lines, 1,10-phenanthroline and its complexes, polyaza-phenanthrenes, and 1,9- and 1,10-diaza-anthracenes have been published. Other specialist reviews are devoted to catalytic methods of obtaining pyridine bases pyridine N-oxides the stereochemistry of quinolizines, indolizines, and pyrrolizines benzothiazinone dioxides 2-quinazolones and their cyclic homologues (e.g. 

Polyaromatics (anthracene and phenanthrene) have also been oxidized by FePcS/H202. This catalytic system is highly influenced by the presence of an organic co-solvent and phosphate ions. Iron tetra-amide complexes are also able to efficiently catalyze the oxidative cleavage of TCP with hydrogen peroxide at basic pH values. ... 

The hypothesis of a mechanism involving oxidative addition of the aryl triflate bond to palladium is further supported by comparing the mixtures of phenanthrenes that are obtained when the Pd(OAc)2/P(o-tol)3 catalytic system is applied to the regioisomeric triflates 120 and 121. Since both these triflates... 

Catalytic properties of complexes of multi-valenced metals with poly(ethylene glycol) (PEG) and polyurethane (PU) have been studied during liquid-phase oxidation processes such as the liquid-phase oxidation of hydrocarbons (phenanthrene, tetralin, cyclohexene), decomposition of hydroperoxides, hydrocarbons and decomposition of hydrogen peroxide [101 -106]. The kinetics of these reactions have been studied. The rate and selectivity of a particular reaction process depend not only on the properties... 

Hypervalent iodine species were demonstrated to have a pronounced catalytic effect on the metalloporphyrin-mediated oxygenations of aromatic hydrocarbons [93]. In particular, the oxidation of anthracene (114) to anthraquinone (115) with Oxone readily occurs at room temperature in aqueous acetonitrile in the presence of 5-20 mol% of iodobenzene and 5 mol% of a water-soluble iron(llI)-porphyrin complex (116) (Scheme 4.57) [93]. 2-ferf-Butylanthracene and phenanthrene also can be oxygenated under similar conditions in the presence of 50 mol% of iodobenzene. The oxidation of styrene in the presence of 20 mol% of iodobenzene leads to a mixture of products of epoxidation and cleavage of the double bond. Partially hydrogenated aromatic hydrocarbons (e.g., 9,10-dihydroanthracene, 1,2,3,4-tetrahydronaphthalene... 

Up to here, it was shown that inclusion of one catalytic specie, like anatase, in the anode allowed increasing the oxidant specie production and the electroosmotic flow rate, but obtained phenanthrene removal was lowered. So next step is to analyze what happen if the catalytic activity is maintained at the anode, but cathode is chosen between different materials. Experimental set-up objective was data collection for two different cathode materials, and also to clarify how much the system becomes affected by inclusion of additional physical barriers like a thick filter paper. 

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