Phosphorylated Hydrazones and Diazophosphonate Synthesis Through Base-Promoted Radical Reactions

Herein, we report a regioselective phosphonylation of aldehyde-derived hydrazones via P-centered radical addition, expanding C─P bond formation to include dialkyl phosphites. Optimization studies established manganese acetate as an efficient oxidant and silver nitrate as the optimal catalyst, enabling mild and efficient radical phosphonylation. Notably, 4-methylbenzenesulfonylhydrazones underwent an unexpected transformation, affording diazo phosphonates instead of phosphonylated products. This study offers a practical and versatile method for C─P bond formation and provides new insights into radical-mediated hydrazone functionalization, with potential applications in pharmaceuticals and materials science.