POCl 3 /Sulfoxide‐ and Acetyl Bromide/Sulfoxide‐Promoted Oxidative Sulfenylation of Indoles

A mild and rapid chemoselective sulfenylation of indoles with thiophenols has been established by the employment of sulfoxide as the oxidant and POCl 3 (phosphorus oxychloride) or AcBr (acetyl bromide) as the activator at ambient temperature. Sulfenylation of indoles at the C3 position can be achieved in the presence of POCl 3 and tetramethylene sulfoxide, while a sulfenylation/bromination cascade was reached by combining AcBr and dimethyl sulfoxide in the reaction system.