- Superoxide oxidation of 1-nitropyrene-cis-dihydrodiols
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KO2 oxidation of cis-4,5-dihydro-4,5-dihydroxy-3-nitropyrene, 1 gives the known lactone, 3-nitro-5H-phenanthro[4,5-bcd]pyran-5-one, 2. Similarly the analogous 4,5-dihydrodiol, 3, gives the known lactone, 1-nitro-5H-phenanthro[4,5-bcd]pyran-5-one, 4. While the yield of 2 is 80%, it is only 16% for 4. A study of the latter oxidation, relying especially on the use of HPLC, led to a change in the conditions that increased the yield of 4 from 16 to 88%. The change was to quench the reaction with H2O2 shortly after it began instead of letting it proceed, as usual, for several hours before quenching with water.
- Abdel-Baky, Samy,Sotiriou-Leventis, Chariklia,Giese, Roger W.
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- Oxidative Dearomatization of Phenols and Polycyclic Aromatics with Hydrogen Peroxide Triggered by Heterogeneous Sulfonic Acids
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We report herein a method for the oxidative dearomatization of phenols and bare polycyclic arenes into the corresponding quinoid derivatives using hydrogen peroxide. The reaction is catalyzed by sulfonic acids and best results were achieved using heterogenized species. The best results using phenols were achieved using a hybrid material, namely a perfluorinated polymer functionalized with sulfonic acid groups supported on silica. The dearomatization of polycyclic aromatic hydrocarbons performed better using the polymeric acid catalyst. These methods operate under mild conditions, using mild and benign oxidants and thus minimizing the formation of waste.
- Pancrazzi, Francesco,Maestri, Giovanni,Maggi, Raimondo,Viscardi, Rosanna
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supporting information
p. 5407 - 5414
(2021/10/25)
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- An efficient C-C bond cleavage of 1,2-diols using tetraethylammonium superoxide
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Tetraethylammonium superoxide, generated in situ by the phase-transfer reaction of potassium superoxide and tetraethylammonium bromide in DMF, brings about an easy cleavage of vicinal diols and related dihydroxy arenes under mild reaction conditions, at room temperature.
- Singh, Krishna Nand,Kumar, Rajesh,Shukla, Ajay Kumar
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p. 1347 - 1351
(2008/09/18)
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- 5-Methoxyphenanthrene-4-carboxylic Acid
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Lead tetraacetate oxidation of phenanthrene-4,5-dicarboxylic acid in acetonitrile with pyridine affords 5-hydroxyphenanthrene-4-carboxylic acid as its lactone, which can be methylated as the sodium salt, giving 5-methoxyphenanthrene-4-carboxylic acid, albeit in poor yield.New spectroscopic evidence (particularly 13C n.m.r.) confirms that 5-formylphenanthrene-4-carboxylic acid, which is an intermediate in the synthesis, exists as the lactol, 4-hydroxyphenanthrooxepin-6(4H)-one.
- Gillis, Richard G.,Porter, Quentin N.
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p. 1007 - 1010
(2007/10/02)
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- Schmidt reaction of some constrained aromatic acids, and related topics
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Schmidt reaction of phthalic acid in 90-98percent sulfuric acid gives anthranilic acid and anthranilazide (major products) by a process considered to involve 3,1-benzoxazin-2,4(1H)-dione as intermediate.Benzimidazol-2-one is produced in this reaction by a secondary process from anthranilazide; it is also produced by photolysis of anthranilazide.Under Schmidt reaction conditions, 1,2,3-benzotriazin-4(3H)-one gives o-azidobenzamide.Under similar conditions, the lactol of 4-formyl-5-phenanthroic acid gives 1-azapyren-2(1H)-one and phenanthrene-4,5-dicarboximide, while phenanthrene-4,5-dicarboxylic acid gives 1-azapyren-2(1H)-one.Diphenic acid yields phenanthridone and 2,2'-diaminobiphenyl in proportions dependent on the sulfuric acid concentration.
- Ruediger, Edward H.,Gandhi, Sham S.,Gibson, Martin S.,Farcasiu, Dan,Uncuta, Cornelia
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p. 577 - 579
(2007/10/02)
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