文摘
Recently, transition-metal-catalyzed radical phosphorylations have provided a direct and useful way to P-substituted compounds. Although a variety of methodologies involving phosphinoyl radicals have been developed, the mechanism of the P–H compounds in the redox process is still unclear. In this work, a mechanistic study on the reduction of Cu(II) by P–H compunds through XAS and EPR spectroscopy has been demonstrated. Two commonly used P–H compounds, diphenylphosphine oxide and dialkyl phosphites, have been selected in this reduction system. The structure of formed Cu(I) species is evidenced through fitting results of the EXAFS spectrum. Furthermore, the halide ion can be a mediator to promote the reduction of Cu(II) by P–H compounds. These spectroscopic investigations provide useful insights into the reactions of P–H compounds, which would be helpful for an understanding of the mechanism and the future design of reactions.