Rhodium complex of monodentate phosphite as a catalyst for olefins hydroformylation

Rhodium complex of a novel monodentate bulky phosphite ligand, tri-1-naphthylphosphite is studied for the hydroformylation of dissimilar alkenes specifically, 1-hexene, styrene, and cyclohexene. The steric attributes of free ligand is investigated by cone angle. The effect of concentration of alkene as well as catalyst, ligand/Rh ratio, pCO and pH2 on the rate of reaction has been studied. For 1-hexene and styrene, the initial rate was found to be zero order with respect to initial alkene concentration and first order with respect to catalyst concentration and H2 partial pressure. For cyclohexene, the reaction was found to be first order with respect to the initial cyclohexene concentration and of slightly positive order with respect to H2 partial pressure. The initial rate of hydroformylation of styrene (at 80 °C, 3.0 MPa syngas pressure) is ∼3.9 times less than that of 1-hexene hydroformylation where as the rate of cyclohexene hydroformylation is ∼87 times less than that of 1-hexene hydroformylation.

A novel monodentate bulky phosphite ligand, tri-1-naphthylphosphite (TNPST) has been synthesized and characterized. The catalytic performance of its Rhodium complex is investigated for the hydroformylation of dissimilar alkenes specifically 1-hexene, styrene, and cyclohexene. The steric attributes of free ligand is investigated by cone angel method.Figure optionsDownload as PowerPoint slide