Tertiary Amines as Ligands in a Four‐Step Tandem Reaction of Hydroformylation and Hydrogenation: An Alternative Route to Industrial Diol Monomers

A highly selective synthesis of diols is presented by simple auto‐tandem catalysis to connect hydroformylation and hydrogenation reactions by a rhodium‐catalyst with tertiary amines as ligands. This system allows the hydroformylation/hydrogenation of non‐conjugated cyclic olefins to selectively provide diols under mild reaction conditions. As a model substrate, the industrially relevant dicyclopentadiene (dcpd) was chosen. With the reaction system [Rh(octanoate) 2 ] 2 and triethylamine, diols are produced in a high yields of up to 79 % with full conversion of intermediate aldehyde and no evidence of olefin hydrogenation. The scope of the reaction was evaluated and the optimised reaction conditions were successfully scaled up to a 2 L reactor. Finally, the Rh/amine catalyst complex was recycled by a simple water extraction of the diol‐product.