Remote Fluorination-Induced Directional Electronic Modulation of Rh Sites for High-Performance Hydroformylation

Heterogeneous catalyst (Rh1/POPs-PPh3) has been successfully applied in the industrial hydroformylation process and offers long-term durability. Nevertheless, although the hydroformylation activity of Rh1/POPs-PPh3 is slightly higher than that of its homogeneous counterpart, it still fails to reach the ideal value. Herein, we developed a remote fluorination strategy to achieve the directional electronic modulation of Rh sites. The optimized Rh1/POPs-PPh3-6F catalyst exhibits a turnover frequency (TOF) that is 2.8 times higher than that of Rh1/POPs-PPh3-0F, maintaining stability throughout 300 h of continuous operation. EXAFS results demonstrate that the remote fluorination strategy does not alter the coordination environment of Rh. Characterizations combined with DFT calculations clarify the electron transmission path and further demonstrate that fluorine-induced electronic redistribution selectively modulates substrate adsorption. Specifically, it facilitates propene adsorption strength and activation, while weakening the CO adsorption strength, an effect driven by the optimized orbital overlap and enhanced π-backdonation. This electronic redistribution reduces the energy barriers for both olefin and CO insertions, thereby dual-governing the acceleration of the catalytic cycle and ultimately boosting catalytic performance.