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Hydrogena tion

Noting that cis alkenes are intermediates in the hydrogenation of alkynes leads us to con sider the possibility of halting hydrogenation at the cis alkene stage If partial hydrogena tion of an alkyne could be achieved it would provide us with methods for preparing... [Pg.375]

Separation, combustion, pyrolysis, hydrogena-tion, anaerobic fermen-tation, aerobic fermen-tation, biophotolysis, partial oxidation, steam reforming, chemical hy-drolysis, enzyme hydrol-ysis, other chemical conversions, natural processes... [Pg.15]

Commercially available hydrogen fluoride usually is not suitable for catalytic hydrogenation because of its sulfur dioxide content An oxidative treatment with manganese dioxide and distillation are needed for the preparation of hydrogena tion-grade hydrogen fluoride [d, 4]... [Pg.942]

A great many materials have been used as catalyst supports in hydrogena-tion, but most of these catalyst have been in a quest for an improved system. The majority of catalyst supports are some form of carbon, alumina, or silica-alumina. Supports such as calcium carbonate or barium sulfate may give better yields of B in reactions of the type A- B- C, exemplified by acetylenes- cjs-olefins, apparently owing to a weaker adsorption of the intermediate B. Large-pore supports that allow ready escape of B may give better selectivities than smaller-pore supports, but other factors may influence selectivity as well. [Pg.4]

Scheme 3.6 Conventional mechanism for the H2-hydrogena-tion of aldehydes, ketones (Q = 0) and imines (Q = NR). Ruthenium remains as Ru" throughout the cycle. The square represents a vacant site on ruthenium. Scheme 3.6 Conventional mechanism for the H2-hydrogena-tion of aldehydes, ketones (Q = 0) and imines (Q = NR). Ruthenium remains as Ru" throughout the cycle. The square represents a vacant site on ruthenium.
The reforming of EG can be accompanied by significant production of acetic acid through bifunctional dehydrogenation/isomerization and dehydration/hydrogena-tion routes over the metal and the support. [Pg.216]

Figure 1.12. Examples of biologically active compounds obtainable via BINAP-Ru catalyzed hydrogena -tion of difunctionalized ketones. Figure 1.12. Examples of biologically active compounds obtainable via BINAP-Ru catalyzed hydrogena -tion of difunctionalized ketones.
Fig. 17.72. Ionic hydrogena-tion/hydrogenolysis of an aromatic ketone (meto-nitroace-tophenone). CF3C00H causes a reversible protonation of the ketone to the ion A. The reducing agent triethylsilane then transfers a hydride ion onto A to form a benzylic alcohol. This alcohol presumably is silylated, protonated, and converted into the benzyl cation B. A second hydride transfer yields the final product. Fig. 17.72. Ionic hydrogena-tion/hydrogenolysis of an aromatic ketone (meto-nitroace-tophenone). CF3C00H causes a reversible protonation of the ketone to the ion A. The reducing agent triethylsilane then transfers a hydride ion onto A to form a benzylic alcohol. This alcohol presumably is silylated, protonated, and converted into the benzyl cation B. A second hydride transfer yields the final product.
Ruhrkohle/VEBA Oel-hydrogenation A coal liquefaction process based on the IG-Hydrogena-tion process. [Pg.312]

This approach goes back to Reilly and Wiswall [79] who were the first to prove that this concept indeed allows the modification of the thermodynamics of hydrogena-tion/dehydrogenation reactions. [Pg.203]

Boc-Thi>OMe Typical Procedure for Conversion of Z into Boc Carbamates by Transfer Hydrogena-tion I l... [Pg.96]

Figure 5. Methanation activity of carbon monoxide hydrogena tion over nickel supported on (a) Nb-O and (b) Nb20g-Si(>2 a a function of reduction treatment. Reduction treatments were ( ) 773K, lh and (A) 873K, 16h. Figure 5. Methanation activity of carbon monoxide hydrogena tion over nickel supported on (a) Nb-O and (b) Nb20g-Si(>2 a a function of reduction treatment. Reduction treatments were ( ) 773K, lh and (A) 873K, 16h.
The positive Cotton effect of the carbonyl group in 115 verified the cis fusion of rings C and D and consequently the a-position of the hydrogen at C-13. This is in accord with the more favored a-hydrogena-tion of the C-12 double bond from the less hindered rear side of 104. [Pg.27]

Enols have also been generated as isolable intermediates in the l,4 -hydrogena-tion of steroidal enones. Under neutral conditions, the enols are readily autoxidized to hydroperoxides, which can be reduced to the corresponding alcohols (Scheme 11)... [Pg.958]

Zuo, X.B., Liu, H., Guo, D., Yang, X. (1999) Enantioselective hydrogena tion of p Tuvates over polymer-stabilized and supported platinum nanoclusters, Tetrahedron, 55, 7787-7804. [Pg.256]


See other pages where Hydrogena tion is mentioned: [Pg.400]    [Pg.46]    [Pg.451]    [Pg.452]    [Pg.397]    [Pg.219]    [Pg.46]    [Pg.251]    [Pg.219]    [Pg.49]    [Pg.38]    [Pg.273]    [Pg.193]    [Pg.257]    [Pg.260]    [Pg.269]    [Pg.284]    [Pg.285]    [Pg.291]    [Pg.299]    [Pg.192]    [Pg.546]    [Pg.581]    [Pg.5]    [Pg.84]    [Pg.402]    [Pg.51]   


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