HOMOGENEOUS HYDROGENATION OF ALK-1-ENES AND ALKYNES CATALYZED BY THE 1--7-C6H5-1,7-(?-C2B10H10) COMPLEX

Article abstract of DOI:10.1016/S0022-328X(00)95263-X

The complex , where carb=-7-C6H5-1,2-C2B10H10, was found to be an effective catalyst for homogeneous hydrogenation of terminal olefins and acetylenes at room temperature and atmospheric or subatmospheric hydrogen pressure.Internal olefins are not hydrogenated, but simple alk-1-enes are readily converted into the corresponding alkanes.Isomerization of the double bond catalyzed by the metal complex occurs at very small extent.Catalytic hydrogenation of olefins having carboxylate substituents on the unsaturated carbon atoms is prevented by the formation of thermally stable chelate hydriodoalkyl complexes of the type .Acetylenes are hydrogenated to alkenes.The alk-1-enes formed in the hydrogenation of the alkynes HC<*>CR in turn undergo the more slow reactions either of hydrogenation to alkanes or isomerization to internal olefins which cannot be further hydrogenated.Hydrogenation of alkynes of the type RC<*>CR' is stereospecifically cis, yielding cis-olefins.Catalyzed cis -> trans isomerization reaction of these internal olefins occurs only to a negligeable extent.