I2-Promoted Deoxygenative Coupling of Indolin-3-ones with Thiols for the Synthesis of 3-Sulfenylindoles

This study aims to develop a facile and efficient synthetic method for the deoxygenative coupling of indolin-3-one derivatives with thiols utilizing I2 as a catalyst. This process proceeded smoothly under mild conditions at room temperature without requiring oxidants and exhibited a broad substrate scope. This transformation involved the deoxygenation of indolin-3-one without the need for a transition-metal catalyst and additional synthetic steps. Furthermore, regioselective C-S bond formation, which is produced at the C2 or C3 position of indolin-3-one, was achieved, depending on the presence or absence of a base.