Formic Acid-Driven Rapid and Green Anti-Markovnikov Hydrothiolation of Styrenes.

A novel formic acid-assisted rapid and efficient route for C-S bond construction via the thiol-ene reaction has been reported. Exclusively, the anti-Markovnikov product was obtained in good to excellent yield using the developed protocol. Various styrenes and thiols bearing different functionalities were well tolerated. The reaction also provided a good yield of sulfones in a one-pot two-step protocol. The developed method is operationally simple, green, metal-free, solvent-free, and having a high atom economy with high regioselectivity.