Alkane derivatives alkene hydrogenation

Just as the alkanes and alkenes had general formulas, the carbon derivatives all have general formulas. The hydrocarbon backbone provides a portion of the general formula, and the functional group provides the other part. In each case, the hydrocarbon derivative is represented by the formula R-, and the hydrocarbon backbone has its own specific formula. The term substituted hydrocarbon is another name for hydrocarbon derivative, because the functional group is substituted for one or more hydrogen atoms in the chemical reaction. 

The history of the oxo reaction is also noteworthy. It was developed originally in Germany in the years following World War 1. At that time, the German chemical industry was faced with inadequate supplies of petroleum. Many German chemists therefore turned to research on ways by which hydrocarbons could be synthesized from smaller building blocks, particularly carbon monoxide and hydrogen derived from coal. The success achieved was remarkable and led to alkane and alkene syntheses known as the Fischer-Tropsch process ... 

Another widely used decarboxylation procedure involves the use of lead tetraacetate. Depending on the nature of the substrate and the reaction conditions, this reagent may transform a carboxylic acid into an alkane or alkene, or into the respective acetoxy derivative (Scheme 2.144). The most favorable conditions for alkane formation utilize a good hydrogen donor as the solvent. Usually this transformation is carried out as a photochemically induced oxidative decarboxylation in chloroform solution, as is exemplified in the conversion of cyclobutanecarboxylic acid in cyclobutane.In contrast, the predominant formation of alkenes occurs in the presence of co-oxidants such as copper acetate. ... 

Alkene hydrogenation, alkane hydrogenolysis, and methanation of CO are used as test reactions for evaluating the catalytic activity of cluster-derived metal catalysts. Catalysts derived from noble metal carbonyl precursors such... 

If a jS-hydrogen is present, one obtains fj -CpCr(CO)3X, > -CpCr(CO)3H, and alkanes and alkenes derived from R . TpMo(CO)3, also a 17-electron complex, reacts with BrCH2CN to give TpMo(CO)3Br and TpMo(CO)3CH2CN . 

While rate coefficients for reactions with OH radicals with the lower members of the alkane and alkene series are well known from laboratory measurements, there exist only a few sporadic data for the higher homologues. It is possible, however, to estimate rate coefficients by an extrapolation of existing data where needed, and this allows us to derive lifetimes also for compounds for which OH rate coefficients have not been determined. Specifically, for the alkanes Greiner (1970a,b) has proposed a formula based on his studies of hydrogen abstraction by OH radicals from saturated hydrocarbons. The expression is... 

Hydrocarbon-derivative compounds do not occur naturally. They are manmade from hydrocarbon compounds, as discussed earlier, with some additional elements added. Hydrocarbon derivatives belong to families just as the hydrocarbons. In order to make hydrocarbon derivatives, hydrogen needs to be removed from the alkane family. Alkene hydrocarbons have one or more double bonds that can be broken and... 

However, it was suggested that if the residual anions could be completely removed from the organoclays, the primary degradation pathway would switch to an elimination-type mechanism [16]. The Hofmann elimination of ammonium compounds was most probably the source of additional amounts of vinyl-type unsaturation found in melt-processed OMMT-PE relative to both the polymer control and the Na+MMT-PE samples [28]. On the other hand, the presence of alkenes was also explained by three possible routes of decomposition (i) pyrolysis of alkanes derived from the major component of the organic part, i.e., hydrogenated tallow (HT) (ii) pyrolysis of the tallow (unsaturated fatty acids used for the preparation of the quaternary ammonium salt) and (iii) decarboxylation of RCOO and RCO radicals [17, 29]. 

The catalyst used is typically platinum, palladium, rhodium, or ruthenium, or sometimes an appropriate derivative. Precise details of the reaction remain vague, but we believe the catalyst surface binds to both the substrate, e.g. an alkene, and hydrogen, weakening or breaking the jr bond of the alkene and the a bond of hydrogen. Sequential addition of hydrogen atoms to the alkene carbons then occurs and generates the alkane, which is then released from the surface. 

The final products derived from 1 1 addition of sydnones to alkenes are usually pyrazoles or dihydropyrazoles. The pyrazoles are formed by oxidation of intermediate dihydropyrazoles. An unusual example of aromatization by elimination of an alkane (toluene) in prefence to hydrogen is illustrated in Scheme 7 <89TL4625>. 

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