Bridging Homogeneous and Heterogeneous Catalysis: Ni@CPOL-dppp&PPh₃-Catalyzed Symmetric H-Phosphonate Diester Synthesis from Sodium Hypophosphite

The biological importance and practical significance of H-phosphonate diesters and their analogues have been the major driving forces for research in various areas of synthetic organic phosphorus chemistry. However, establishment of a gentle and environmentally friendly method to avoid use of toxic PCl3 is still the biggest challenge in this area. As potential alternatives to PCl3, we studied the progress in the conversion of cheap and green inorganic salt sodium hypophosphite (NaH2PO2) and alcohol into various H-phosphonate diesters [(RO)2P(O)H] with the release of H2 by using the heterogeneous single-atom site Ni@CPOL-dppp&PPh3 catalyst. Remarkably, the catalyst exhibited outstanding catalytic performance, allowing for the efficient conversion of a wide range of various alcohols to their corresponding H-phosphonate diesters in good to high yields. This new route completely avoids the use of phosphorus trichloride (PCl3) and promises a convenient real process for making H-phosphonate diesters in industry and laboratory. Moreover, the present study provides meaningful insights into the development of well-defined heterogeneous catalysts guided by homogeneous catalysis.