DFT modeling study of ethylene hydroformylation catalyzed by organic phosphine-rhodium catalyst

The ethylene hydroformylation catalyzed by the organic phosphinerhodium catalyst was computed by means of the density functional theory at the B3LYP/6-31G(d, p) level (Rh and P are at the LANL2DZ + Polar basis sets) and the structures for the intermediates, the transition states, and the products were optimized. As shown, there are two domination reaction paths for this reaction and it passes through coordination of ethylene to rhodium, ethylene insertion, addition of phosphine, carbonyl insertion, oxidative addition of H-2, and aldehyde reductive elimination with the regeneration of the catalyst. During the ethylene insertion, the carbonyl insertion, the oxidative addition of H-2, and the aldehyde reductive elimination, the three-membered structures are formed. As predicted, the hydroformylation originates from the cis-isomers of the catalyst, the oxidative addition of H-2 is the rate-determining step, and the aldehyde reductive elimination is un-reversed.