Phosphorus coordinated Rh single-atom sites on nanodiamond as highly regioselective catalyst for hydroformylation of olefins

Single-atom Rh catalysts present superior activity relative to homogeneous catalyst in olefins hydroformylation, yet with limited success in regioselectivity control. In the present work, we develop a phosphorus coordinated Rh-1 single-atom catalyst with nanodiamond as support. Benefiting from this unique structure, the catalyst exhibits excellent activity and regioselectivity in hydroformylation of arylethylenes with wide substrate generality, i.e., with high conversion (>99%) and high regioselectivity (>90%), which is comparable with the homogeneous counterparts. The coordination interaction between Rh-1 and surface phosphorus species is clarified by P-31 solid-state NMR and X-ray absorption spectroscopy (XAS). Rh single atoms are firmly anchored over nanodiamond through Rh-P bonds, guaranteeing good stability in the hydroformation of styrene even after six runs. Finally, by using this catalyst, two kinds of pharmaceutical molecules, Ibuprofen and Fendiline, are synthesized efficiently with high yields, demonstrating a new prospect of single-atom catalyst in pharmaceutical synthesis. Single-atom Rh catalysts present superior activity in olefins hydroformylation, yet with limited success in regioselectivity control. Here the authors develop a Rh1 single-atom catalyst with nanodiamond as support, with which good to excellent regioselectivities to branched aldehydes in hydroformylation of terminal olefins are achieved.

Automated summary

Single-atom Rh catalysts show superior activity in olefins hydroformylation but limited success in regioselectivity control. By developing a Rh1 single-atom catalyst with nanodiamond as support, the catalyst achieved good to excellent regioselectivities in hydroformylation of arylethylenes, comparable to homogeneous counterparts. The coordination interaction between Rh-1 and surface phosphorus species was clarified by P-31 solid-state NMR and X-ray absorption spectroscopy.