A Mild and Direct C(sp3)-S Cross-Coupling of Oxindoles with Thiols: Synthesis of Unsymmetrical 3-Thiooxindoles.

Herein, an operationally simple and mild strategy to construct sulfenation of oxindoles with a series of thiols in the absence of transition metals was developed. This methodology provides an efficient way to directly form a C-S bond at the C-3 position of oxindoles under mild reaction conditions with a cheap and common solvent and base in moderate to good yields.