Redox-Active Sulfonyl Hydrazones as Programmable Sulfur Transfer for Nickel-Catalyzed C–S Coupling with Organic Halides

The utilization of hydrazones as carbon or nitrogen sources in transition-metal-catalyzed synthetic chemistry has been well developed; however, their application as electrophilic sulfur cation surrogates remains uncharted territory. Herein, we report the unexpected discovery that sulfonyl hydrazones serve as programmable sulfur transfer in nickel-catalyzed C-S coupling with a broad range of organic halides. This method forges the nickel catalytic cycle toward selective C-S cross-coupling while effectively suppressing the competing formation of conventional C-C coupling products. Mechanistic studies indicate that the success of this strategy stems from the favorable reduction potential imparted by the electron-withdrawing SO₂R group, which enables manganese to reduce the hydrazones in situ, generating key electrophilic sulfur species to engage in a distinctive nickel catalytic cycle that favors C-S over C-C bond formation.