Catalytic Lewis acid activation of thionyl chloride: Application to the synthesis of aryl sulfinyl chlorides catalyzed by bismuth(III) salts

The catalytic Lewis acid activation of thionyl chloride (1) has been achieved and applied to the preparation of aryl sulfinyl chlorides using BiCI 3 (2), or Bi(OTf);XH H O (with 1 < x ≤ 4) (3) as catalysts. 3 is by far more efficient than 2 and the scope of this reaction is restricted to electron rich aromatics.