Hydrogenolysis, organic compounds

Hydrogenation.. The chemical addition of hydrogen to another substance, usually an unsaturated organic compound, as opposed to hydrogenolysis. 

Hydrogenolysis. The incidence of bond cleavage in an organic compound with the immediate addition of hydrogen to each dangling fragment. 

Water does not dissolve many organic compounds but it can be used as a solvent, especially in hydrogenations of acids and their salts. It may have some deleterious effects for example it was found to enhance hydrogenolysis of vinylic halogens [66],... 

Hydrogenolysis is the replacement of a halogen substituent on an organic compound by a hydrogen as... 

Hydrogenolysis of carbon-sulfur bonds is a widely utilized reaction for removing sulfur from sulfur-containing organic compounds, and is known as desulfurization or hydrodesulfurization. Bougault et al. used Raney Ni for the first time for the desulfurization of aliphatic thioalcohols and disulfides in neutral and alkaline solution.126 Since then the reaction has been widely applied, for example, for organic syntheses, purification of solvents and substrates, structural studies, and determination of sulfur contents.127... 

Nystrom RF, Berger CRA (1958) Reduction of organic compounds by mixed hydrides. II Hydrogenolysis of ketones and alcohols. J Amer Chem Soc 80, 2896-2898. 

Let us consider as an example a hydrogenolysis reaction utilizing the concept of multiple sites for adsorption and competition between hydrogen and an organic compound for surface sites. The model presented below considers an uniform surface and does not include all the features related to possible defects present at the surface of real catalysts. 

Werpy, T.A., Frye, J.G.J., Zacher, A.H. and Miller, D.J. (2003) Hydrogenolysis of 6-Caibon Sugars and Other Organic Compounds, W02003035582. 

Acetophenone hydrogenated 3.5 hrs. with rhodium platinum oxide in acetic acid at room temp, and atmospheric pressure -> cyclohexylmethylcarbinol. Y 80%.—Rhodium platinum (3 1) oxide is more active than PtOg and PdO in the hydrogenation of various organic compounds under ordinary conditions, and is especially effective where it is desired to avoid hydrogenolysis. F. e. s. S. Nishimura, Bull. Ghem. Soc. Japan 54, 32 (1961). 

Only scare data is available in the literature on the application of rhenium containing mono- or bimetallic catalysts in the hydrogenolysis of esters to alcohols. Decades ago Broadbent and co-workers studied the hydrogenation of organic carbonyl compounds (aldehydes, ketones, esters, anhydrides, acids,... 

Benzyl and Allyl Carbon Atoms Hydrogenolysis of a carbon-heteroatom bond is extremely fast if the heteroatom is connected to allylic or benzylic carbon atoms. The benzylic compounds are used very frequently in organic chemistry as protecting groups. Because of its great importance the benzylic compounds are discussed separately in the next section. 

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