Synthesis of 2-Aryl-3-arylsulfonylindoles and 2-Anilino-3-arylsulfonylindoles from 2-(Arylsulfonyl)methylanilines Using the Aza-Wittig Reaction of Iminophosphoranes - Takahashi, Masahiko; Suga, Daishi (Synthesis, 1998)