The Ruthenium-Catalyzed Hydrogenation of Aromatic Amines Promoted by Lithium Hydroxide

Abstract
The effects of the addition of various alkaline substances on the ruthenium-catalyzed hydrogenation of aromatic amines have been investigated at raised temperature and pressure. The addition of lithium hydroxide was shown to be the most effective for rapid and selective hydrogenation of aromatic amines. The effect of various solvents on the hydrogenolysis of carbon-nitrogen bonds has also been studied in the hydrogenation of m-xylene-α,α′-diamine and N,N-dimethyl-p-phenylenediamine. Generally, the hydrogenation was fast and the amount of the hydrogenolysis was small in secondary alcohols. Typical examples of the syntheses of alicyclic amines are given.