Rhodium Pyrrolylphosphine Complexes as Highly Active and Selective Catalysts for Propene Hydroformylation: The Effect of Water and Aldehyde on the Reaction Regioselectivity

Iridium-phosphine ligand complexes as an alternative to rhodium-based catalysts for the efficient hydroformylation of propene

Expensive rhodium (Rh)-based catalysts have been widely used for the hydroformylation of propene. To find a cheaper and effective alternative to these Rh-based catalysts, herein, a series of phosphine ligands were used to coordinate with iridium, and their catalytic reactivities for the hydroformylation of propene were systematically investigated in this study. The effects of different phosphine ligands, pressures, temperatures, and catalyst dosages on the hydroformylation of propene were investigated. Tripyridyl phosphine iridium Ir2(cod)2Cl2-P(3-py)3 (Ir(I)-L5) and its derivatives exhibit the highest catalytic reactivity. Surprisingly, the catalytic reactivity of Ir(I)-L5 is higher than that of Rh2(cod)2Cl2-P(3-py)3 (Rh(I)-L5). When the Ir(I)-L5 complex is used as the catalyst, reactions performed in a polar solvent gave higher turnover number (TON) values than those in a non-polar solvent. Up to a TON of 503 can be obtained. Different n-butyraldehyde/iso-butyraldehyde (n/i) ratios can be obtained by adjusting the phosphine ligands or the proportion of gas pressure. The catalyst showed good reusability in five recycling experiments. Furthermore, based on DFT theoretical calculations, a probable reaction mechanism was proposed. It is reliable that an Ir-based catalyst can be considered as a highly effective catalyst for the hydroformylation of propylene with CO.

The mechanism of MOF as the heterogeneous catalyst for propene hydroformylation: The DFT study

Metal-organic framework which was composed of metal center and organic linkers possessing the similar structure with the homogeneous metal-complex catalyst for hydroformylation, thus it could be potentially used as the...

Study and modular synthesis of unsymmetrical bis(phosphino)pyrrole ligands

We report the facile and modular synthesis of unsymmetrical 1,2-bis(phosphino)pyrrole ligands and their coordination chemistry. These ligands offer a promising alternative to their 1,2-bis(phosphino)benzene congeners, retaining a similar steric profile with attenuated electron donation. Proof-of-principle application of a bis(phosphino)pyrrole ligand in a nickel-catalyzed C-N cross-coupling reaction under mild conditions is demonstrated.

Hydroformylation of unsaturated esters and 2,3-dihydrofuran under solventless conditions at room temperature catalysed by rhodium N-pyrrolyl phosphine catalysts

Complexes of the type HRh(CO)L₃ (where L is an N-pyrrolyl phosphine, e.g. P(NC₄H₄)₃, Ph(NC₄H₄)₂, or PPh₂(NC₄H₄)) were applied in the hydroformylation of less reactive unsaturated substrates (allyl acetate, butyl acrylate, methyl acrylate, 2,3-dihydrofuran, vinyl acetate).