Highly regioselective synthesis of branched saturated aldehydes by tandem hydroformylation/isomerization/hydrogenation of 1-arylbutadienes

Rh-catalyzed tandem hydroformylation/isomerization/hydrogenation of various 1-arylbutadienes toward the corresponding branched saturated aldehydes were performed in the presence of monodentate phosphine ligand PPh₃. After investigating different reaction parameters such as P-ligands and solvents, the conversion of substrates (including electron withdrawing and electron donating groups on aromatic rings, up to 99%) and chemical/regioselectivity of the target products (up to 98% and 99/1 for B/L) were improved using DMF as solvent. The [Rh(cod)Cl]₂/PPh₃ catalytic system had good substrate universality in terms of substituents on the phenyl ring and provided a simple synthesis method for branched saturated aldehydes.