The Formation of C—H Bonds: Hydrogenation and Related Reactions

Abstract

Diverse heterogeneous and homogeneous metal systems are known to catalyse hydrogenation reactions. The general field of hydrogenation in organic chemistry is well surveyed in recent reference books [851, 1154, 1503] and review articles [177, 450, 852]. Heterogeneous species such as Raney nickel and palladium on carbon are often the most convenient and sometimes the most active catalysts to use for the hydrogenation of organic molecules. They assist the reduction of a wide variety of substrates including alkenes, alkynes, arenes, aldehydes, ketones and nitro compounds. Indeed, the diversity of functional groups that can be hydrogenated under mild conditions, together with the range of other reactions (such as hydrogenolysis, H/D scrambling and isomerization) that are catalysed by the same heterogeneous species, is sometimes a major disadvantage — heterogeneous catalysts often lack specificity.