Hydrogenation of dienones in presence of cyanoamine complexes of cobalt

1. The cyanoamine complexes of cobalt catalyze under mild conditions the selective hydrogenation of dienones to unsaturated ketones. 2. Hydrogen adds to crotonolideneacetone predominantly at the C=C bond adjacent to the carbonyl group. The amount of formed 5-hepten-2-one in the catalyzate reaches 85%. 3. In contrast to pentacyanocobaltate, the cyanoamine complexes of cobalt catalyze the isomerizatton of 5-hepten-2-one to 4-hepten-2-one and 3-hepten-2-one.