Inert to oxidation

Sulfur. Low sulfur stocks and EV sulfur-accelerated systems have better aging resistance. Normally, the oxidation rate increases with the amount of sulfur used in the cure. The increased rate may be due to activation of adjacent C—H groups by high levels of combined sulfur. Saturated sulfides are more inert to oxidation than aHyUc sulfides. Polysulfidic cross-links impart excessive hardening of SBR as compared to more stable monosulfidic cross-links. 

Aldehydes do not co-oxidize alkanes due to a huge difference in the reactivity of these two classes of organic compounds. Alkanes are almost inert to oxidation at room temperature and can be treated as inert solvents toward oxidized aldehydes [35]. Olefins and alkylaromatic hydrocarbons are co-oxidized with aldehydes. The addition of alkylaromatic hydrocarbon (R2H) to benzaldehyde (R1H) retards the rate of the initiated oxidation [36-39]. The rate of co-oxidation obeys the equation [37] ... 

A liquid perfluorocarbon was being used as solvent in an oxidation by oxygen under pressure more energy was released than expected [1], It is cautioned that fluorocarbons are not inert to oxidation, presumably to carbonyl fluoride. An explosion has been experienced with perfluorotoluene in like circumstances [2], A correspondent reports that perfluorotoluene is flammable in air, more saturated perfluorocarbons in pure oxygen [3], Another detailed the combustion performance of polytetrafluoroethylene 148 kcal/mole ignition temperature not below 465°C at 7000 psi of oxygen [4], the product is mostly carbonyl fluoride. Other oxidants may also present a risk in extreme circumstances. 

The redox and complexation chemistry of alditol/Cr(VI) systems64 and the my<9-inositol/Cr(VI) system65 has been reported. In the first case, when an excess of the alditol over Cr(VI) is used, the secondary OH groups are inert to oxidation, and alditols are selectively oxidized at the primary OH group to yield the aldonic acid as the only oxidation product. The corresponding reaction involves a Cr(VI) —> Cr(V) —> Cr(III) reduction pathway, and the relative rate of each step depends on [H+] at... 

Azaaromatic systems are usually oxidized to their A-oxides. Peracetic acid is the oxidant most used though for unstable substrates perbenzoic or perphthalic acids are preferable. They permit the use of non-polar solvents and milder conditions. Heterocycles relatively inert to oxidation can be converted to N-oxides by the more active performic or trifluoroperacetic acids. m-Chloroperbenzoic acid (MCPBA) also gives good results, especially when other easily oxidizable groups are present in heterocyclic molecule and therefore the question of selectivity is important. Thus, 2-aminopyridine was successfully converted with MCPBA into 2-aminopyridine A-oxide. 

Fluorine is a reactive, almost colorless gas of F2 molecules. Most of the fluorine produced by industry is used to make the volatile solid UF6 used for processing nuclear fuel (Section 17.12). Much of the rest is used in the production of SF6 for electrical equipment and to make fluorinated carbon compounds, such as Teflon (polytetrafluoroethylene). Most fluoro-substituted hydrocarbons are relatively inert chemically they are inert to oxidation by air, hot nitric acid, concentrated sulfuric acid, and other strong oxidizing agents. 

Catalyzed oxidations.1 In catalytic procedures with Ru04, periodate or hypochlorite are generally used as the stoichiometric oxidants. The addition of acetonitrile, which is inert to oxidation but an effective ligand for lower valent transition metals, results in much higher yields. A third solvent, chloroform, also plays a significant part. The ruthenium tetroxide is generated in situ from RuCl, (H20)n or Ru02 with sodium or potassium metaperiodate sodium hypochlorite is less effective. 

Aldehydes are readily oxidized to yield earboxylic acids, but ketones are inert to oxidation. Which is the most likely explanation regarding this difference in reactivity ... 

The sterically hindered character of the double bond in adamantylidene adamantane is also reflected by the fact that it is inert to oxidation by potassium permanganate and that although the corresponding epoxide may be formed, the epoxide is inert to hydrolysis conditioning. Adamantylidene adamantane glycol may be prepared, however, by treating adamantanone with sodium metal in xylene 36S). 

Tertiary alcohols are relatively inert to oxidation by chromic acid however, tertiary 1,2-diols are rapidly cleaved by chromic acid provided they are capable of forming a cyclic chromate ester (61) (Reaction XXXVI). 

Ley and Barton s observation that di-4-methoxyphenyltelluride could be used catalytically was the first entry into the use of in situ generated selenoxides or telluroxides as catalysts. As shown in Fig. 8, a variety of different nucleophiles can be introduced via the selenoxide or telluroxide followed by reductive elimination to generate oxidized product and reduced selenide or telluride. If the nucleophile is relatively inert to oxidation by hydrogen peroxide, then the reduced selenide or telluride can be reoxidized by hydrogen peroxide and the overall oxidation of the nucleophile becomes catalytic in the selenide or telluride. In the case of thiols, disulfides are the final product and the selenides or tellurides exhibit thiolperox-idase-like activity 60-62 64 82 83 If halide salts (chloride, bromide, iodide) are the nucleophiles, then positive halogen sources are the oxidized products and the selenides and tellurides exhibit haloperoxidase-like activity.84-88 The phenoxypro-pyltelluride 59 has been used as a catalyst for the iodination and bromination of a variety of organic substrates as shown in Fig. 24.87... 

Ketones are generally inert to oxidation, but can be oxidized to carboxylic acids with strong oxidizing agents. 

However the epoxidation of olefins lacking allylic and other reactive C-H bonds with molecular oxygen has recently been achieved on silver catalysts (Table 1). In 1997 the Eastman Chemical Company started the manufacture of 3,4-epoxy-1-butene, the product of mono-epoxidation of butadiene, on a semiworks production scale (entry 1). Remarkably enough the presence of benzylic hydrogen, as in / -methyl styrene (entry 5), drives the oxidation towards combustion, while sterically hindered allylic C-H s, as in norbornene (entry 6), are inert to oxidation. 

Reversible electrochemical lithium deintercalation from 2D and 3D materials is important for applications in lithium-ion batteries. New developments have been realized in two classes of materials that show exceptionally promising properties as cathode materials. The first includes mixed layered oxides exemplified by LijMn Nij, Co ]02, where the Mn remains inert to oxidation/reduction and acts as a framework stabilizer while the other elements carry the redox load. Another class that shows much potential is metal phosphates, which includes olivine-type LiFeP04, and the NASICON-related frameworks Li3M2(P04)3. 

The third uncoupling pathway, or branch point, occurs at the Compound I species VII. If the substrate is bound too far away from the Compound I oxygen, or if the functional group closest to this oxygen is inert to oxidation, the hfetime of VII will be increased and electron-transfer reduction of VII to II can become the dominant reaction. The overall result is the use of two molecules of NAD(P)H to reduce O2 to two water molecules. This is the reaction catalyzed by oxidases and this oxidase uncouphng pathway has been... 

Tricker, K. J., L. A. Ash, and W. Jones (1979). On the anomalous inertness to oxidation of the surface regions of vivianite a Fe conversion electron and transmission Mossbauer study. J. Inorg. Nucl. Chem. 41, 891-93. 

Just as aromatic rings are generally inert to oxidation, they re also inert to catalytic hydrogenation under conditions that reduce typical alkene double bonds. As a result, it s possible to reduce an alkene double bond selectively in the presence of an aromatic ring. I or example, 4-phenyl-3-buten-2-one is reduced to 4-phenyl-2-butanone at room temperature and atmospheric pressure using a palladium cataly st. Neither the benzene ring nor the ketone carbonyl group is affected. 

Substrates with more than one alkyl group are oxidized to dicarboxylic acids. Compounds without a benzylic C-H bond are inert to oxidation. 

Molecules with a cross section diameter greater than about 0.60 nm caimot diffuse into the TS-1 channels and are, therefore, not oxidized. This size restriction limits this system essentially to the oxidation of linear molecules and monocyclic aromatic rings with at most, small substituents. Even with these limitations, TS-1, and to a lesser extent TS-2, is an effective catalyst for the selective oxidation of a number of different types of organic compounds. Thirty percent hydrogen peroxide is the most commonly used oxidant. The more bulky alkyl peroxides are not effective because of their inability to diffuse into the zeolite channels to react with the titanium sites. While the oxidation of most primary and secondary alcohols occurs with reasonable ease, methanol is sufficiently inert to oxidation under the common reaction conditions that it is the solvent of choice for most TS-1 catalyzed reactions. 2 26,27... 

Just as aromatic rings are inert to oxidation under most conditions, they re also inert to catalytic hydrogenation under conditions that reduce typical... 

Anodic Substitution - In the past few years a number of anodic substitution processes have been discovered.22 The scope of these reactions is defined and often they provide the method of choice for performing the particular transformation. These processes generally use non-aqueous solvents which have a combination of polarity and relative inertness to oxidation. A general scheme is FH + Nuc - FNuc + H+. Both aromatic and aliphatic com-... 

Indeed, the former example illustrates a severe limitation of anodic aromatic substitution. Unactivated aliphatic positions can also be substituted if solvents which are inert to oxidation are employed.27... 

The aprotic solvent, liq SOj, is inert to oxidation and is promising for anodic pro-cesses , such as for electrolytic preparation of stable solutions of aromatic dications that are labile under normal nonaqueous conditions. 

---