Single-Electron Transfer between CuX2 and Thiols Determined by Extended X-Ray Absorption Fine Structure Analysis: Application in Markovnikov-Type Hydrothiolation of Styrenes.

Transition-metal mediated C-S bond formation using thiol compounds has been widely used in recent years. However, there has been less focus on the interaction between the metal and thiol compounds. In this work, we have successfully evidenced the single-electron transfer between CuX2 and thiophenol utilizing EXAFS. The fitting EXAFS results reveal that two halide anions are coordinated with the CuI center, whereas no sulfur atom is observed in the first coordination sphere. This CuI ate complex serves as the key intermediate for the proton transfer in the application of Markovnikov-type hydrothiolation reactions.