Rh2(II)-Catalyzed Nitro-Group Migration Reactions: Selective Synthesis of 3-Nitroindoles from β-Nitro Styryl Azides

Abstract
Rhodium carboxylate complexes (1 mol %) catalyze the migration of electron-withdrawing groups to selectively produce 3-substituted indoles from β-substituted styryl azides. The relative order of migratorial aptitude for this transformation is ester ≪ amide < H < sulfonyl < benzoyl ≪ nitro.