HCo(CO)3-Catalyzed Propene Hydroformylation. Insight into Detailed Mechanism

Abstract

The entire catalytic cycle of propene hydroformylation using HCo(CO)3 as an active catalyst has been systematically investigated at the B3LYP density functional level of theory. It is found that the most stable π-complex HCo(CO)3(η2-H2CCHCH3) has a CC double bond coordination in the equatorial position, and the subsequent olefin insertion (alkylation) process is reversible, in agreement with the experimental finding. The hydride migratory insertion is accompanied by Co(CO)3 pseudorotation, leading to the Co···H−C agostic stabilized (iso)propyl complex (C3H7)Co(CO)3 with the alkyl group at the axial position and thus does not take place on a Cs symmetry potential energy surface. The regioselectivity is mainly determined by the relative stability of the alkyl cobalt tetracarbonyl complexes (C3H7)Co(CO)4 from the exothermic and irreversible CO addition to the alkyl cobalt tricarbonyl complexes (C3H7)Co(CO)3, which is therefore a thermodynamic controlled process. The CO insertion process (carbonylation) proce...