Regioselective C−S Bond Formation between Flavones and Arylsulfonyl Chlorides through the Use of Ammonium Iodide

A novel and regioselective ammonium iodide mediated C−S bond formation protocol involving flavones and sulfonyl chlorides to generate different ArS‐substituted flavone derivatives in high yields was developed. Different from existing metal‐free C−S bond formation protocols with the use of PPh 3 or I 2 as the catalyst, this method provides an alternative way of constructing C−S bonds through the use of NH 4 I as a catalyst, which makes it highly valuable for the efficient synthesis of thioether compounds.