Synthesis of Industrial Primary Diamines via Intermediate Diols – Combining Hydroformylation, Hydrogenation and Amination

Abstract A homogenous transition metal catalysis that combines hydroformylation, hydrogenation and direct amination presents an elegant multi‐step pathway for synthesising primary diamines from olefins and ammonia. The valuable intermediate TCD‐diamine is obtained, which has a wide range of industrial applications as a monomer building block. The rhodium‐catalysed hydrohydroxymethylation step converts non‐conjugated dienes to the intermediate diols. Ammonia is added in a second ruthenium‐catalysed amination step to obtain primary diamines. The conditions for both reactions were first optimised independently and combined to design a tandem reaction. For the amination reaction of the diol, excellent diamine yields of up to 88 % in toluene were achieved. An analysis of the interactions between the two catalytic systems demonstrated that the conditions of both single reaction steps counteract each other, meaning the presence of either rhodium or ruthenium blocks the other respective reaction. Using a two‐step approach, optimised reaction conditions were applied to achieve equally high diamine yields of 88 %.