Transition-Metal-Free Cleavage of C-C Triple Bonds in Aromatic Alkynes with S8 and Amides Leading to Aryl Thioamides.

A novel transition-metal-free cleavage reaction of C-C triple bonds in aromatic alkynes with S8 and amides furnishes aryl thioamides in moderate to excellent yields. The remarkable features of this thioamidation include the metal-free cleavage of C-C triple bond, mild reaction conditions, as well as wide substrate scope that is particularly compatible with some internal aromatic alkynes and acetamides.