Hydrogenation Technique

Augustine, R. L. 1965, Catalytic Hydrogenation Techniques and Applications In Organic Synthesis, M. Dekker New York... 

M. Ereifelder, in Practical Catalytic Hydrogenation Techniques andApplications,]ohn Wiley Sons, Inc., New York, 1971, Chapt. 16. 

Catalytic reduction of secondary functionaUties in sulfonates, in which the sulfonate moiety is unchanged, is accompHshed using standard hydrogenation techniques (21). Sulfonic acids may be converted to the corresponding silyl esters in very high yields (22). 

R. L. Augustine, Catalytic Hydrogenation, Techniques and Applications in Organic Synthesis , M. Dekker, Inc., New York (1965). 

M. Freifelder, Practical Catalytic Hydrogenation, Technique and Applications, Wiley-Interscience, New York, 1971, p. 398. 

Some hydrogenation techniques may induce surface damage that increases the H concentration at the surface. Some of the compounds tend to decompose during hydrogenation for example, the surface of InP decomposes with the formation of phosphine (PH3). This problem has been controlled by encapsulating the substrate with a hydrogen-permeable layer. 

Before we begin to discuss various hydrogenation techniques, the reader should be forewarned that little is known about the detailed physics of... 

Reductions of these ring systems are common. Most often, active hydrogen techniques are employed to cleave weak heteroatom-heteroatom bonds. Reductions of the glycoluril derivatives are less common due to the lack of such a weak bond. Some recent examples include reactions by Chan et al. <2003TL395> who employed Raney nickel and hydrogen to effect cleavage of an N-O bond in their synthesis of new heterocyclic compounds via 1,3-dipolar cycloaddition chemistry (Equation 15). 

Cyclohexane is an essential intermediate for the synthesis of nylon-6,6. The purity level required for the use of cyclohexane, especially for its oxidation, is higher than 99%. This purity can be obtained by the benzene hydrogenation technique. The conversion is highly exothermic and is favored by low temperature, and high hydrogen partial pressure. 

Open the stopcock of the burette, inject from a syringe through the inlet port 0.5 mol of the compound to be hydrogenated as a liquid or as an ethanolic solution when hydrogenation will proceed automatically as in the external hydrogenation technique. 

R. L. Augustine (1965). Catalytic Hydrogenation Techniques and Application in Organic Synthesis. London Arnold M. Hudlicky (1984). Reduction in Organic Chemistry. Chichester Horwood P. N. Rylander (1985). Hydrogenation methods , in Best Synthetic Methods. Eds A. R. Katritzky, O. Meth-Cohn and C. V. Rees. London Academic Press. 

The mechanical properties as a function of heat treatment temperature are shown in Figure 9 for fibers prepared by the Kyukoshi method. Fiber heat-treated to 2000°C or higher have strengths above 3GPa (435 kpsi) and tensile moduli of the order of 500 GPa (72 Mpsi). The present authors now believe that, in the near future, it will be possible to produce carbon fiber of equivalent properties by selection of suitable raw pitch materials and by development of specialized pretreatment procedures for the pitch to replace the extensive hydrogenation technique described here. 

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