Ruthenium on alumina

The crude, but essentially pure, dibenzo-18-crown-6 obtained from the Organic Syntheses preparation described above (Eq. 3.11) may be hydrogenated in M-butanol solution over 5% ruthenium on alumina, in a stainless steel autoclave at 1,000 p.s.i.. Di-cyclohexano-18-crown-6 is obtained from this treatment in 58—69% yield as a mixture of crystalline diastereomers having a melting range of 38-54°. 

The solvent for ammonia may have an important influence. In reduction of C,o unsaturated dinitriles to primary amines over ruthenium-on-alumina, ammonia-/-butanol proved the preferred system normal alcohols gave poor rates and secondary alcohols produced N-alkylated products 18). 

The 5% ruthenium-on-alumina catalyst is available from Engelhard Industries. 

Some papers have been published that examine Ru/SiC>2 as a catalyst in the Methanation step. These papers looked at the effects of hydrogen and temperature as well as how a Cl-modified Ru/SiC)2 catalyst performs. The Cl decreased catalytic activity, but it enhanced selectivity for methane formation -even though it was present on the catalyst only during the initial stages of the reaction77, 8. For extremely low temperature applications (i.e., < 180°C), one company offers a catalyst with 0.3% ruthenium on alumina. This catalyst does not contain any NiO or CaO166. 

Recently Yamaguchi and Mizuno[ 113] reported ruthenium on alumina to be a powerful and recyclable catalyst for selective alcohol oxidation. This method displayed a large substrate scope (Eq. 29, Table 4) and tolerates the presence of sulfur and nitrogen groups. Only primary aliphatic alcohols required the addition of hydroquinone. TOFs in the range from 4 h 1 (for secondary allylic alcohols) to 18 h 1 (for 2-octanol) were obtained in trifluorotoluene, while in the solvent-free oxidation at 150 °C a TOF of 300 h 1 was observed for 2-octanol. 

The number of possible octahydro derivatives of the monomethyl-and dimethylnaphthalenes is so large that identification is impractical. With naphthalene, however, analysis is possible. Not only are the six octalin isomers identifiable (66), but eventually all were detected in the products of partial hydrogenation of naphthalene with a ruthenium-on-alumina catalyst at 75° and 1000 psig. The results obtained by gas chromatography are shown in Table VIII. All six isomers were detected... 

Ruthenium-on-carbon and ruthenium-on-alumina also are effective for reduction of a phenolic ring in polycyclic compounds. Anilines are hydrogenated under the same con-... 

Reduction of anilines to cyclohexylamines over RuOj works successfully on a series of nuclear substituted substrates, at 90-125°C, 8 X 10 kPa, in alcohols or without solvent". Yields of 92% are obtained in the preparation of diamines such as bis(4-aminocyclohexyl) methane, the product being mostly cis,cis and cis,trans isomers . Phenylenediamines are reduced to the 1,3-diamine (91%) or to the 1,4-diamine (88%) over ruthenium-on-alumina in ethanol. The c/j-isomer predominates (70-84%) in a number of solvents and over a range of experimental conditions ". Synthetic advantages can be taken from some side reactions. Hydrogenation of 3,4-diaminobenzoic acid can lead to a mixture of bicyclic lactams that lack an amino substituent . Selective hydrogenation of trisubstituted aniline 9 affords lactame 10, an intermediate in the total synthesis of ibogamine. ... 

Other experiments on nitrogen fixation have used transition metai compiexes of nitrogen.74 One used a tungsten nitrogen compiex with a ruthenium hydrogen complex at 55°C to produce a 55% yield (based on tungsten) of ammonia.75 Intermetallic compounds of iron and titanium have been used with ruthenium on alumina to make some... 

Fig. 14. Data illustrating effect of 7-irradiation on the methanation of carbon dioxide over supported Ru catalysts comprising ruthenium on alumina (Ru/Al) or ruthenium in molecular sieve (Ru/M). Effects of 7-irradiation at the indicated temperature on the growth of methane product observed from a continuous flow of C02 in a H2 carrier gas over (i) Ru/M and (ii) Ru/Al. Note the growth in methane yields from C02—H2 reaction at different temperatures as a function of 7 dose and its decay with time subsequent to removal of the catalyst from the 7-source.

Materials. Zeolites A, X, Y, and L were from Union Carbide Corporation, and Zeolite Z was a synthetic large port mordenite from Norton Company. Chabasite was a crystallographically very pure natural zeolite from an Hungarian deposit. Zeolite Y is an aluminum-deficient Y zeolite prepared by H4EDTA treatment. The hexammine complex of was from Strem Chemicals. The ruthenium-on-alumina catalyst was from Ventron. 

K. Kaneda, M. Wayaku, T. Imanaka, and S. Teranishi, Chem. Letters, 231 (1976). Ruthenium on alumina. 

Catalytic oxygenation. Dibenzothiophene (1) is converted into the 5,5-dioxide in high yield when heated in benzene with air in the presence of 5% ruthenium on alumina (100° and 70 atm.). A suitable catalyst can also be obtained... 

OXYGENATION Cuprous chloride. Oxygen. Oxygen, singlet. Ruthenium on alumina. 

Figure 4.28 Effect of 21 ppm sulfur dioxide on the activity of a ruthenium/alumina catalyst for the preferential oxidation of carbon monoxide the catalyst contained 1.6 wt.% ruthenium on alumina reaction temperature 150°C [338].

---