Oxidative coupling oxygen

Oxidative coupling of methane to yield C2 and higher hydrocarbons 358 Direct partial oxidation of methane to produce methanol and other oxygenates 360... 

It is postulated that the mechanism of the silane-mediated reaction involves silane oxidative addition to nickel(O) followed by diene hydrometallation to afford the nickel -jr-allyl complex A-16. Insertion of the appendant aldehyde provides the nickel alkoxide B-12, which upon oxygen-silicon reductive elimination affords the silyl protected product 71c along with nickel(O). Silane oxidative addition to nickel(O) closes the catalytic cycle. In contrast, the Bu 2Al(acac)-mediated reaction is believed to involve a pathway initiated by oxidative coupling of the diene and... 

Oxidative polymerization of phenol derivatives is also important pathway in vivo, and one example is the formation of melanin from tyrosine catalyzed by the Cu enzyme, tyrosinase. The pathway from tyrosine to melanin is described by Raper (7) and Mason (8) as Scheme 8 the oxygenation of tyrosine to 4-(3,4-dihydro-xyphenyl)-L-alanin (dopa), its subsequent oxidation to dopaqui-none, its oxidative cyclization to dopachrome and succeeding decarboxylation to 5,6-dihydroxyindole, and the oxidative coupling of the products leads to the melanin polymer. The oxidation of dopa to melanin was attempted here by using Cu as the catalyst. 

Poly(phenylene oxide) PPO, or poly(phenylene ether) PPE, is an engineering polymer developed by General Electric. It concerns the oxidative coupling of phenols discovered in 1956 by Allan S. Hay [21], Oxidative coupling leads to the formation of carbon-oxygen bonds between carbon atoms 2,4, and 6 and the phenolic oxygen atom. To avoid coupling with carbon atoms 2 and 6, alkyl substituents at these two positions were introduced. In addition to the polymer a 4,4 dimer is formed, named diphenoquinone (DPQ). The... 

Methane and Toluene to Styrene Basic catalysts in the presence of oxygen and/or air are reported to be attractive catalysts for this reaction. Most research was performed in the late 1980s and early 1990s. The fundamentals resemble the oxidative coupling reaction of methane to ethylene. 

Despite many applications of the iron-mediated carbazole synthesis, the access to 2-oxygenated tricyclic carbazole alkaloids using this method is limited due to the moderate yields for the oxidative cyclization [88,90]. In this respect, the molybdenum-mediated oxidative coupling of an arylamine and cyclohexene 2a represents a complementary method. The construction of the carbazole framework is achieved by consecutive molybdenum-mediated C-C and C-N bond formation. The cationic molybdenum complex, required for the electrophilic aromatic substitution, is easily prepared (Scheme 23). 

To add to the complexity yet further, we note that the solution obtained from the iron-containing ore could itself undergo reaction. Ferrous ion can be readily oxidized by oxygen from the air, so a solution that originally contained just Fe could also contain Fe- " " if left standing for some time, where the oxidation process depletes the amount of Fe + in solution. In generating Fe " ", such aerial oxidation has also caused yet another redox couple to form in this case, for the Fe- ", Fe " couple is 0.77 V. 

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