Katalysator und Verfahren zur Hydrierung von olefinisch ungesättigten Verbindungen

A hydrogenation catalyst comprising (A) a transition metal compound in which a group having a heterocyclic skeleton is bonded to Ti, Zr or Hf through an oxygen atom or a nitrogen atom, a representative of which compound is bis(cyclopentadienyl)titanium bis(tetrahydrofurfuryloxy) and (B) an organic compound, halide or hydride of a metal of Groups I to III of the Periodic Table or comprising the constituent (A), the constituent (B) and (C) a polar, organic compound such as an alcohol, a carboxylic acid or the like. An olefinically unsaturated compound can be hydrogenated with a high efficiency by contacting the compound with hydrogen in the presence of the above catalyst in an inert, organic solvent. The above catalyst has a very high catalytic activity, is excellent in hydrogenation selectivity and thermal resistance, also excellent in storage stability and maintainability of catalytic activity and is hardly affected by the co-existing impurities.