C-H Oxidation with NHPI Catalyst

C-H Oxidation with NHPI Catalyst

Overall Score4
  • Generality
  • Reagent Availability
  • Experimental User Friendliness
  • General Characteristics

An organocatalyst N-hydroxyphthalimide (NHPI) forms the strongly oxidizing N-oxyl radical species (PINO) in the presence of appropriate oxidizing agents. This radical is highly active in abstracting a hydrogen from hydrocarbons.

This is a valuable catalytic system in which C(sp3)-H bonds can be oxidized under relatively mild conditions. Further developments, especially the improvement of regioselectivity, are awaited.

  • General References

  • Ishii, Y.; Nakayama, K.; Takeno, M.; Sakaguchi, S.; Iwahama, T.; Nishiyama, Y. J. Org. Chem. 1995, 60, 3934. DOI: 10.1021/jo00118a002


  • Reaction Mechanism


  • Examples

In recent years, the NHPI system has been extended to the direct fluorination[1] and amination[2] of sp3 C-H bonds.



  • Experimental Procedure

  • Experimental Tips

  • References

[1] Amaoka, Y.; Nagatomo, M.; Inoue, M. Org. Lett. 2013, 15, 2160. DOI: 10.1021/ol4006757
[2] Amaoka, Y.; Kamijo, S.; Hoshikawa, T.; Inoue, M. J. Org. Chem. 2012, 77, 9959. DOI: 10.1021/jo301840e

  • Related Reactions

Catalytic C-H Oxidation

  • Related Books

  • External Links

N-Oxy Radical Chemistry (The Kanai Group at University of Tokyo, PDF)