Metal- and solvent-free direct C-H thiolation of aromatics with sulfonyl chloride
A simple, efficient and green method for the direct thiolation of aromatic compounds using commercially available sulfonyl chlorides as the sulfur source was disclosed under metal- and solvent-free conditions. The C-S bond was constructed via direct C-H functionalization of diverse aromatics under an oxygen atmosphere. In this process, various diaryl sulfides were synthesized in moderate to excellent yields. This protocol shows broad substrate scope and good functional group tolerance. Moreover, a gram-scale experiment was also conducted to prove the prospect of this method for the scale-up synthesis of diaryl sulfides. Mechanistic studies indicate that this procedure probably undergo a radical pathway.