Regioselective Thiolation of Arenes and Heteroarenes: C–H Functionalization Strategy for C–S Bond Formation

A facile transition-metal-free oxidative cross-dehydrogenative coupling reaction involving selective formation of a C–S bond leading to the synthesis of arylthiobenzoxazoles, heteroarylthiobenzoxazoles, and arylthiobenzothiazoles has been described. This highly regioselective C–H functionalization reaction with electron-rich aromatic systems including heteroaromatics is achieved by reversing the reactivity of sulfur in the presence of a suitable oxidant and strong acid.