Hydrogenation of Naphthalene

Obtained by the catalytic hydrogenation of naphthalene. Owing to the presence of one aromatic ring it can be nitrated and sulphon-ated. It is non-toxic and is used as a solvent for fats, oils and resins. 

Decahydronaphthalene [91-17-8] (Decalin) is the product of complete hydrogenation of naphthalene. Like Tetralin, it is a clear, colorless Hquid with... 

Stereochemistry and Mechanism of Hydrogenation of Naphthalenes on Transition Metal Catalysts and Conformational Analysis of the Products A. W. Weitkamp... 

Weitkamp, A.W., Stereochemistry and mechanism of hydrogenation of naphthalene on transition metal catalysts and conformational analysis of the products. Adv. Catal., 18,1-110 (1968). 

Schmitz, A.D., G. Bowers, and C. Song, Shape-selective hydrogenation of naphthalene over zeolite-supported Pt and Pd catalysts. Catal. Today, 31,45-56 (1996). 

Another possibility to increase the diastereoselectivity in an asymmetric synthesis can arise from different thermodynamic stabilities of the diasteieoisomeric products. If the thermodynamic stabilities of these are different enough, then, under conditions of equilibrium, a complete conversion of the less stable into the more stable can be achieved. For example, the diastereoselective hydrogenation of naphthalene derivates over Pd/C catalyst leads to a mixture of dihydronaphtalenes in which the cA-isomer predominates. The conversion of this isomer into the tram occurs by changing the properties of the reaction medium, namely by equilibration with a base. For such a purpose, NaOMe in IHF can be used [263], Generally, such an increase in stability in the six-membered rings can result from a rearrangement of the substituents from an axial to an equatorial position. 

Dealkylation, heteropoly compunds, 41 160-161, 170-174 Deamination, 27 259 Pd(NH3>/ ions, 39 142 Debye-Waller factor, 21 177 Decahydronaphthalenes conformation of, 18 17-19 isomeric, formation of in hydrogenation of naphthalenes, 18 23-20 rrans-Decalin... 

Detailed studies have been conducted on the selectivity of hydrogenation of naphthalene.67 The reaction proceeds via tetrahydronaphthalene as an intermediate and eventually yields a mixture of the isomeric decalins ... 

Almost exclusive formation of the corresponding tetrahydro derivatives in the partial hydrogenation of naphthalene and anthracene are observed with all-cw addition of the hydrogens. 

Less activity than that observed in the HDS reaction is seen for the hydrogenation of naphthalene (Figure 27.6(b)). All three catalysts exhibit comparable hydrogenation activity as evidence by the rates in Table 27.3. Tetralin is found to be the main product of the reaction with little decalin produced. Even though the sulfated hematite shows the highest percentage of hydrogenation, the oxynitride and the oxycarbide are more active per unit area of catalyst (Table 27.3). 

The catalytic hydrogenation of naphthalene produces 80.0 kcal/mol (335 kJ/mol) of heat. Calculate the resonance stabilization of naphthalene. Do you think naphthalene should be termed aromatic ... 

Scheme 9.5 Hydrogenation of naphthalene note, the other possible octalin isomers are usually converted to the two shown by doublebond migration, since the C=C bond is most stable when most heavily substituted.

Figure 1.1 Variations in catalytic activity as a function of the degree of leaching with NiAb (O) and C02AI9 ( ) (a) hydrogenation of cyclohexanone (1 ml) in f-BuOH (10 ml) at40°C and atmospheric hydrogen pressure over 0.08 g of catalytic metal (b) hydrogenation of naphthalene (3 g) to tetrahydronaphthalene in cyclohexane (10 ml) at 60°C and 8.5 1.5 MPa H2 over 0.08 g of catalytic metal (c) hydrogenation of benzene (15 ml) in cyclohexane (5 ml) at 80°C and 7.5 2.5 MPa H2 over 0.08 g of catalytic metal. (From Nishimura, S. Kawashima, M. Inoue, S. Takeoka, S. Shimizu, M. Takagi, Y.Appl. Catal. 1991, 76, 26. Reproduced with permission of Elsevier Science.)...

Usually o.v-dccalin is formed more selectively from tetralin than from naphthalene. Baker and Schuetz obtained a mixture of 77% cis- and 23% frans-decalin in the hydrogenation of naphthalene over Adams platinum oxide in acetic acid-ether at 25°C and 12.8 MPa H2, while cA-decalin was obtained exclusively in the hydrogenation of tetralin in acetic acid under similar conditions.23... 

Catalytic hydrogenation of benzene under pressure by using Raney Ni as a catalyst results in the addition of three molar equivalents of hydrogen. First, benzene is converted into cyclohexadiene, which is reduced to cyclohexene. The hydrogenation of cyclohexadiene and cyclohexene is faster than the hydrogenation of benzene (aromatic compound). Similarly, catalytic hydrogenation of naphthalene in the presence of a Ni catalyst gives tetralin and then decalin. 

Naphthalene is reduced to 1,4-dihydronaphthalene by sodium and alcohol. Isomerization of this product to 3,4-dihydronaphthalene occurs with sodamide in liquid ammonia. Tetrahydronaphthalene (tetralin) is formed from naphthalene by sodium in amyl alcohol or by reduction with nickel-aluminum alloy and aqueous alkali. Catalytic hydrogenation of naphthalene can be stopped at the tetralin stage over copper chromite, Raney nickel, or alkali metal catalysts. cis-Decahydronaphthalene is produced by high-pressure hydrogenation of tetralin over Adams catalyst, whereas a mixture of cis- and trans-decalins is obtained from naphthalene under the same conditions. ... 

With nickel(II) 2-ethylhexanoate and triethylaluminum, tetralin (59) is obtained by hydrogenation of naphthalene (55). Polycyclic aromatics, such as anthracene (57 equation 8), 9-methylanthracene and 9-trifluoroacetylanthracene, are partially hydrogenated to 1,2,3,4-tetrahydroanthracene derivatives by use of [Rh(DPPE)(arene)]+ in methanol and by ruthenium hydride complexes having triphenylphosphine ligands... 

Hydrogenation of cyclopentadiene Hydrogenation of nitrobenzene Hydrogenation of naphthalene to tetraline... 

The hydrogenation of biphenyls over Raney nickel proceeds in a marmer similar to that observed for the hydrogenation of naphthalenes. The hydrogenation of p-phenylphenol (25) takes place over a Pd/C catalyst at 125°C... 

Derivation Hydrogenation of naphthalene in the presence of a catalyst at 150C. 

The hydrogenation of monocyclic aromatics has been extensively studied and is thoroughly covered in reviews by Smith (8), Siegel and Dunkel (9), and Amano and Parravano (10). The hydrogenation of phenanthrene was intensively studied and is reported in the classic papers of Linstead and co-workers (11). By comparison the naphthalenes had been largely neglected. As early as 1901 Sabatier and Sen-derens (12) disclosed the vapor phase hydrogenation of naphthalene to... 

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