An Unusual Copper Catalyzed Iodine Mediated Aziridination of Olefins with the Direct Use of p‐Toluenesulphonamide

Abstract

p‐Toluenesulphonamide/I₂ was found to be an efficient system for the copper catalyzed aziridination of olefins in good yields under very mild conditions.

Keywords:

• Aziridination
• copper
• iodine
• olefins
• p‐toluenesulphonamide

Notes

¹ Typical experimental procedure: To a stirred mixture of Cu (OTf)₂ (18 mg, 5 mol%) and 4‐methylstyrene (118 mg, 1 mmol) in acetonitrile (5 mL) was added p‐toluenesulphonamide (205 mg, 1.2 mmol), iodine (303 mg, 1.2 mmol) and powdered 5Å molecular sieves (100 mg) under a nitrogen atmosphere at 25°C. Stirring was further continued for 3.5 h. The reaction progress was monitored by TLC (SiO₂) using ethylacetate/hexane (4:6) as solvent system. After completion, solvent was evaporated under reduced pressure. The residue obtained was purified by passing through a short silica gel column using hexane/ethyl acetate (4:6) as eluent. Evaporation of the solvent yielded N‐(p‐tolylsulphonyl)‐2‐(p‐methylphenyl)aziridine (Yield 230 mg, 80%). IR ν_max (cm⁻¹) 3034, 1600, 1516, 1360, 1158; ¹H NMR (δ ppm) 2.30 (s, 3H), 2.36 (d, J = 4.2 Hz, 1H), 2.42 (s, 3H), 2.96 (d, 7.16 Hz, 1H)), 3.73 (dd, 7.16, 4.2 Hz, 1H), 7.33–7.09 (m, 6H), 7.87 (d, 2H). Similarly other aziridines were prepared.