Catalytic Oxidation of Phenols to p-Quinones with the Hydrogen Peroxide and Methyltrioxorhenium(VII) System

The oxidation of dibenzothiophene using oxidovanadium(IV)-containing nanofibres as catalyst

“…Studies have shown that hydrogen peroxide appears to be a promising oxidizing agent in the catalyzed oxidation of sulfur compounds in fuels due to the fact that it offers a high amount of active oxygen and produces only water as a by-product. [18][19][20][21][22][23][24][25] The activity and selectivity of metal complexes immobilized on polymer microspheres have been reported in our previous studies to be as efficient as unsupported metal complexes. [26][27][28][29] In an attempt to improve the surface area of the polymeric support, electropsun polymer fibres have also been reportedly employed as an alternative.…”

Synthesis and Spectroscopic Characterization of [1′-14C]Ubiquinone-2, [1′-14C]-5-Demethoxy-5-hydroxyubiquinone-2, and [1′-14C]-5-Demethoxyubiquinone-2

“…Purification by distillation afforded the phenol 9 in a total yield of 70% from 1,3-cyclohexadione (12). Oxidation of this phenol derivative 9 with potassium nitrosodisulfonate (Fremy's salt) [19,20] gave ubiquinone-0 (30), which was purified by silica gel chromatography to yield the benzoquinone 30 (68%).…”

Vitamin E Metabolites: Synthesis of [D2]‐ and [D3]‐γ‐CEHC

“…According to this method, the reaction of 12 with ClCO 2 Et gave the corresponding bis(ethoxycarbonyl) derivative, whose treatment with NaBD 4 in D 2 O/THF directly provided [D 3 ]-dimethylphenol 13 in 71 % yield. Preparation of DMHQ from 2,3-dimethylphenol is generally performed through the oxidation of 2,3-dimethylphenol to the corresponding 1,4-benzoquinone by strong oxidants and transition metals [24] or by coupling with diazotized sulfanilic acid followed by reduction-oxidation steps, [16] usually in only fair yields. We were attracted by the procedure described for the multigram-scale synthesis of 2,3-bis(bromomethyl)-1,4-dimethoxybenzene, [16] in which the key step is the high-yield- ing nucleophilic substitution of bromide in 4-bromo-2,3-dimethylmethoxybenzene with methoxide catalyzed by CuI.…”