Enhancement of hydroformylation performance via increasing the phosphine ligand concentration in porous organic polymer catalysts

Abstract

The development of highly efficient and stable Rh-based heterogeneous catalysts for hydroformylation of heavier olefins is of both high fundamental and industrial interest, yet there still remains a tremendous challenge. In this contribution, a series of porous organic polymers bearing various concentrations of triphenylphosphine (PPh3) moieties, a ligand of industrial choice, was synthesized and their performance in the hydroformylation of styrene, 1-ocetene, and 2-ocetene were investigated after metalation with Rh species. Both concentration of PPh3 moieties and pore structure of the polymers were found to influence the catalytic performance. The polymer-based rhodium catalysts demonstrated an increase in catalytic activity, selectivity, and stability when the concentration of PPh3 was increased and the porous polymer constructed by the functional PPh3 monomer (POL-PPh3) was found to be optimal among all the solid ligands tested. We anticipate these results will form the basis for a constructive perspective in the development of high performance heterogeneous Rh-based hydroformylation catalysts. Moreover, our observations indicate the considerable potential of porous organic polymers (POPs) as a new generation of heterogeneous catalytic platforms that may prove effective when targeting important but highly challenging reactions.