Deallyloxylative C‐H Sulfenylation of (Hetero)arenes by Allyl Sulfoxides in Water

A green and efficient protocol for direct C‐H sulfenylation of arenes and heteroarenes including indoles using readily available allyl sulfoxides as the sulfur source was developed under metal‐free conditions in water. In this process, allyl sulfoxide undergoes 2,3‐sigmatropic rearrangement (Mislow rearrangement) to sulfenate ester, which in turn reacts with a broad range of arenes and heteroarenes (as thiophile) to offer various sulfides. A variety of allyl sulfoxides can be employed to sulfenate indoles with allyl alcohol as the only byproduct. Moreover, a gram‐scale experiment was also conducted to acertain the efficiency of this method for the scale‐up synthesis of diaryl sulfides. Furthermore, disulfenylation was carried out by simply increasing the concentration of allyl sulfoxides under analogous reaction conditions.