Amine synthesis via carbonylation reactions: aminomethylation

The preparation of aliphatic amines and alicyclic diamines by reaction of o lefins, synthesis gas and dimethylamine, known as aminomethylation, was inv estigated. Synthesis involves homogeneous rhodium and ruthenium catalysts o r mixtures thereof at very low concentrations. Employing 3-12 ppm Rh and 50 -100 ppm Ru results in up to 97% selectivity towards the amines at conversi ons of up to 98% if aliphatic mono-olefins are used as starting materials. At high catalyst concentrations (173 ppm Rh, 2660 ppm Ru) the corresponding diamine is obtained from dicyclopentadiene in 89% yield. The influence of reaction parameters and catalyst ratios on the n/i-selectivity of the produ ct indicates the scope as well as the limits of such a multi-step synthesis for a commercial process. (C) 1999 Elsevier Science B.V. All rights reserv ed.