Anodic Oxidation of Aliphatic Ethers

The electrochemical oxidation of aliphatic ethers is known from the literature and was investigated in more detail by Hoechst308). The use of glassy carbon anodes led to a considerable increase in the current efficiencies and extended the range of useful 

CHj—OCH3 CH30H H3ltNS0tCH3 CH2-0CH2-0CH3 CH OCH3)2 

CH2-OCH3 glassy carbon anode ch2-och3 CH2-OCH3 

The oxidation of amines is very well documented in the scientific literature. Little work has been done in this area in industry (patent literature) over the past few years, however. One reason for this is certainly the frequently unsatisfactory yields in these reactions. 

Usingp-phenylenediamine as a starting material, Celanese 309) attempted to produce new monomers for engineering plastics  

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Ahphatic ethers are usually difficult to oxidize because their oxidation potentials are very high. The use of an electroauxiliary enables the anodic oxidation of aliphatic ethers under mild conditions. For example, the anodic oxidaticm of a-silyl ethers in an alcohol as solvent leads to the formation of... 

The introduction of a hydroxy group in an aliphatic compound already containing a simple oxygen function, such as an ether, does not affect the oxidation potential significantly. Consequently, the products of anodic hydroxylation of aliphatic ethers may survive the conditions necessary for the oxidation of substrate. For example, tetrahydrofuran has successfully been converted to 2-hydroxytetrahydrofuran by anodic oxidation in 1 M H2SO4 at Pt, as in Eq. (15) [29]. However, the hydroxylation of diisoalkyl ethers results in highly oxidized products such as ketones and acids [30]. 

Anodic Oxidation of Alcohols and Aliphatic Ethers 3.1.7.1 Electrosynthesis of Carboxylic Acids... 

Simons process — Electrochemical polyfluorination reactions of organic compounds are the only efficient way to industrial production of perfluorinated compounds. The reaction proceeds in the solution of KF in liquid HF (b.p. 19.5 °C), where the starting substances as alcohols, amines, ethers, esters, aliphatic hydrocarbons and halo-hydrocarbons, aromatic and heterocyclic compounds, sulfo- or carboxylic acids are dissolved. During anodic oxidation, splitting of the C-H bonds and saturation of the C=C bonds occur and fluorine atoms are introduced. 

For PEMFCs, the solid electrolytes are polymer membranes polymers modified to include ions, usually sulfonic groups. One of the most widely used membranes today is the polymer Nafion , created by the DuPont company. These membranes have aliphatic perfluorinated backbones with ether-linked side chains ending in sulfonate cation exchange groups [6, 7], Nafion is a copolymer of tetrafluoroethylene and sulfonyl fluoride vinyl ether [8] and has a semi-crystalline structure [9], This structure (which resembles Teflon ) gives Nafion long-term stability in oxidative or reductive conditions. The sulfonic groups of the polymers facilitate the transport of protons. The polymers consist of hydrophilic and hydrophobic domains that allow the transport of protons from the anode to the cathode [10, 11],... 

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