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Hydrogenolysis carbon-metal bond

In both systems the hydrogen molecule is apparently split into ions, rather than atoms. Weight is lent to this conclusion by the fact that the order of increasing ease of hydrogenolysis of phenyl derivatives is Ca, Li, Na, K, Rb, and Cs this is also the order of increasing polarity of the carbon-metal bond. [Pg.199]

Hydrogen. Hydrogen, on the other hand, can cleave many carbon-metal bonds smoothly with the formation of the corresponding hydrocarbon and metal hydride. In a remarkable example of such hydrogenolysis phenylpotassium has been found to be cleaved by hydrogen at ordinary temperatures in the absence of pressure or catalysts (43) ... [Pg.66]

Alternatively, one can envisage a direct hydrogenolysis of the carbon-metal bond to form the alkane and the metal hydride. The driving force would be the liberation of the weaker acid (RH) by the stronger acid (H2). [Pg.91]

Reaction of Organometallic Complexes with Particles of Transition Elements The Stepwise Hydrogenolysis of Metal-Carbon Bonds... [Pg.185]

Hydrogenolysis of the C-C bond takes place on different metal catalysts but the rupture of the nonpolarized C-C bond is more difficult than cleavage of the more polarized carbon-heteroatom bonds.482-486... [Pg.190]

Hydrodehalogenation - that is, hydrogenolysis of the carbon-halogen bond -involves the displacement of a halogen bound to carbon by a hydrogen atom. This chapter is devoted to dehalogenations mediated by transition-metal complexes (Eq. (1)) ... [Pg.513]

Since in C2-unit hydrogenolysis both carbon atoms of the C—C bond to be broken must be primary or secondary (isobutane cannot cleave in C2-unit mode through adsorption of its tertiary carbon atom), Anderson formulated the cleavage of neohexane according to Eq. (11.80) involving carbon-metal double bonds (1,2-dicarbene mechanism) 267... [Pg.658]

Rhenium Sulfides and Selenides.208 209 These catalysts are characterized by their outstanding resistance to poisoning and minimal tendency to cause the hydrogenolysis of carbon-sulfur bonds than the base metal sulfides. Rhenium heptasulfide is easily prepared from boiling 6M hydrochloric acid solutions of perrhenate with hydrogen sulfide. It has been noted that occasional exposure of the dried, powdered catalyst to the atmosphere is not deleterious. [Pg.43]

These reactions are discussed in treatises on organic chemistry. Hydrogenolysis of metal- or nonmetal-carbon bonds are used for small-scale specialty chemical syntheses ... [Pg.235]

Aromatic ketones represent a rather special case in dissolving metal reductions. Under many conditions pinacol formation is the predominent reaction path (see Volume 3, Chapter 2.6). Also, the reduction potentials of aromatic carbonyl compounds are approximately 1 V less negative than their aliphatic counterparts. The reductions of aromatic ketones by metals in ammonia are further complicated by the fact that hydrogenolysis of the carbon-oxygen bond can take place (Chapter 1.13, this volume) and Birch reduction may intervene (Chapter 3.4, this volume). [Pg.114]

A potentially useful chemoselective dissolving metal reagent for the reduction of aromatic ketones in the presence of other functional groups is the combination Zn-DMSO and aqueous potassium hydroxide. In three examples (benzophenone, fluorenone and 4-benzoylpyridine), the yields of secondary alcohols were over 90%. Two other ketones (xanthone and thioxanthone) gave mixtures of alcohol and the hydrocarbon obtained by hydrogenolysis of a carbon-oxygen bond. ... [Pg.115]


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See also in sourсe #XX -- [ Pg.176 ]




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Bonds carbon metal

Bonds carbon-metal bond

Bonds hydrogenolysis

Metal hydrogenolysis

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