NO elimination

Only sulfoxidation, and no elimination, occurs when the hydrochloride of 2 (R = Me) is treated with sodium periodate at room temperature.3 Ketone 4, which represents the tautomeric form of dibenzo[6,/]thiepin-10-ol, can be sulfoxidized with hydrogen peroxide at room temperature to provide sulfoxide 5 in 56% yield however, at reflux temperature oxidation occurs additionally at the carbon atom next to the oxo group and sulfone 6 is isolated in 79% yield.3... 

The aim of the reaction of 15a with Cl—P=C(SiMe3)Ph was to synthesize the 2,3,1-diphosphasilabuta-1,3-diene derivative 42 (Scheme 11). However, it turned out that the Cl—P bond of the phosphaalkene exclusively adds to the Si=P bond, forming the addition product 43, which probably has the ( >isomeric structure.45 The corresponding (Z)-isomer 43 was not formed. On heating of 43, even for 8 hours at 110°C, no elimination of /Pr3SiCl was observed. Instead, ( )/(Z)-isomerization simply occurred (43 and 43 in the molar ratio of 1 0.8). 

The elimination from the zirconium alkoxide B (Scheme 8.23) to give the 1,4-diene also proceeds through cationic activation. An independently prepared sample of pure B (X = Cl) would not undergo elimination unless a catalytic amount of AgC104 (or TMSC104, which is the probable chain carrier in this elimination reaction) was added. If AgAsF6 is used as the promoter for the reaction sequence, only the first (addition) step takes place and no elimination to the diene is observed [51],... 

Steam is invariably present in a real exhaust gas of motor vehieles in relatively high concentration due to the fuel combustion. The influence of water vapor on catalytic performances should not be ignored when dealing with the aim to develop a practical TWCs. Cu/ZSM-5 catalysts once were regarded as suitable substitutes to precious metal catalysts for NO elimination[78], nevertheless, they are susceptible to hydrothermal dealumination leading to a permanent loss of activity[79], Perovskites have a higher hydrothermal stability than zeolites[35]. Although perovskites were expected to be potential autocatalysts in the presence of water[80], few reports related to the influence of water on the reactants adsorption, the perovskite physicochemical properties, and the catalytic performance in NO-SCR were previously documented. The H2O deactivation mechanism is also far from well established. 

Following the reports of the effect of nitrogen doping anatase, visible light photocatalysis has also been reported for SrTiOs (NO elimination), MOx-ZnO (where M = W, V or Fe for acetaldehyde decomposition), and TaON, 135,136 methanol oxidation ). 

Of particular interest are the last two examples. Apparently, intramolecular hydrogen abstraction leads quantitatively to cyclobutanols in a-diketones, with no elimination being observed. The phosphorescence yields are, of course, cut drastically by this efficient chemical reaction.396... 

Vercellotti et al. (65) studied the rates of / -elimination for O-benzyl ethers of O-glycosyl-N-(2,4-dinitrophenyl)-L-serine and L-threonine methyl esters in non-aqueous solvents using various bases. The corresponding acetyl derivatives of 2-acetamido-2-deoxy-D-galactose were also included. Generally, these substances were highly reactive, but the nature of the solvent and the base type were influencing factors. Thus, no elimination occurred in benzene when trimethylamine was used as base. 

The selection of reagents is governed by availability, cost, and, more importantly, the possible intrusion of side reactions. Thus in the above example, the action of the strongly basic ethoxide ion on t-butyl bromide would give rise to extensive alkene formation on the other hand little or no elimination would occur by the alternative reaction route. In general therefore, secondary or tertiary alkyl groups can only be incorporated into ethers by the Williamson synthesis by way of the corresponding alkoxide ions in reaction with a primary halide. 

Dimethylnitramine has been used as a simple model for cyclic nitramines because it is easier to deal with experimentally and theoretically than RDX and HMX, and it undergoes some of the same kinds of reactions N-NO2 bond fission, nitro-nitrite isomerization (which can be followed by NO elimination), and HONO elimination. However, even though it seemingly presents fewer problems than do the large nitramines, its decomposition mechanism is not fully resolved. 

The reaction products are simply (no step of separation from the zeolite catalyst) and totally (no elimination of the volatile products) recovered in the cooling trap allowing a good mass balance even without use of an internal standard. 

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