Journal of the Korean Chemical Society (대한화학회지)

Korean Chemical Society (대한화학회)
권호 표지

Oxidation of Benzyl Ethers in Sodium Hypochlorite Mediated Piperidine-1-oxyl System

촉매량의 Piperidine-1-oxyl과 NaOCl계에서 벤질 에테르 유도체들의 산화 반응

  • Cho, Nam Sook (Department of Chemistry, Chungnam National University) ;
  • Park, Chan Heun (Department of Chemistry, Chungnam National University)
  • Published : 19950800
Download PDF
⟨ Previous Next ⟩

Abstract

The oxidation of various benzyl ethers and benzyl alkyl ethers to benzoates has been studied in two-phase system of $CH_3CO_2Et$ and aqueous NaOCl (6.6 mol eq.). The oxidant N-oxo-4-methoxy-2,2,6,6-tetramethylpiperidium bromide (N-oxoammonium salt) was prepared in situ and recycled by addition of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (0.03 mol eq., 4-methoxy-TEMPO), co-catalyst KBr (0.03mol eq.) and second oxidant NaOCl. Thus the catalytic amount of 4-methoxy-TEMPO was used. An adjustment of the pH value of below 8.0 was also required for this reaction with 2.5 hr of reaction time at 0∼5$^{\circ}C$. Under these conditions benzyl ethers were oxidized to benzoates. The selectivity of oxidation of benzyl alkyl ethers is dependent on the acidity of hydrogen and steric effect of alkyl group.

여러가지 비대칭 벤질 에테르들과 벤질 알킬 에테르들을 $CH_3CO_2Et$-NaOCI수용액(6.6 mol eq.)의 2상 용매계에서 4-methoxy-2, 2, 6, 6,-tetramethylpiperidine-1-oxyl(0.03 mol eq., 4-methoxy-TEMPO)을 이용하여 산화시키면 벤조에이트로 산화가 일어난다. 4-methoxy-TEMPO는 2차 산화제인 NaOCI에 의하여 본반응의 산화제인 N-oxo-4-2, 2, 6, 6, -tetramethyl-piperidium 염(N-oxoammonium 염)으로 변환된다. N-oxoammonium 염은 에테르를 산화시키고 N-hydroxy-4-methoxy-2, 2, 6, 6,-tetramethylpiperidine(hydroxyamine)으로 환원된다. Hydroxy-amine은 NaOCI에 의하여 N-oxoammonium 염으로 순환 재생되므로 4-methoxy-TEMPO는 촉매량 사용하였다. 이 반응은 또한 조촉매인 KBr(0.03 mol eq.)가 필수적이고 반응 중 pH는 8.0 이하로 유지되어야 한다. 0 - 5$^{\circ}C$의 반응 온도로 2.5시간 반응시키면 대부분 벤조에이트로 산화 되었다. 벤질 알킬 에테르들의 선택성 산화는 수소의 산도와 알킬기의 입체효과에 영향을 받음이 고찰되었다.

Keywords

References

  1. Bull. Chem. Soc. Jap. v.62 Kajigaeshi, S.;Kawamukai, H.;Fujisaki, S.
  2. J. Chem. Soc. Chem. Comm. Bressan, M.;Morvillo, A.
  3. J. Org. Chem. v.46 Carlsen, P. H. J.;Katsuki, T.;Martin, V. S.;Sharpless, K. B.
  4. J. Am. Chem. Soc. v.80 Berkowiz, L. M.;Rylander, P. N.
  5. Tetrahedron v.27 Juenge, E. C.;Corey, M. D.;Beal, D. A.
  6. J. Org. Chem. v.49 Bonadies, F.;Di Fabio, R.
  7. J. Am. Chem. Soc. v.105 Wolfe, S.;Ingold, C. F.
  8. J. Org. Chem. v.42 Ho, T. L.;Olah, G. A.
  9. Tetrahedron Lett. v.23 Nwaukwa, S. O.;Keehn, P. M.
  10. J. Chem. Soc. Chem. Commun Harrison, I. T.;Harrison, S.
  11. Chem. Rev. v.69 Musqurave, O. C.
  12. J. Am. Chem. Soc. v.94 Snyder, C. D.;Rapoport, H.
  13. J. Am. Chem. Soc. v.98 Olah, G. A.;Welch, J.;Ho, T. L.
  14. J. Am. Chem. Soc. v.100 Olah, G. A.;Welch, J.
  15. J. Org. Chem. v.46 Bal, B. S.;Kochhar, K. S.;Pinnick, H. W.
  16. J. Org. Chem. v.35 Ratcliffe, R..;Rodehorst, R.
  17. J. Angew. Chem. Int. Ed. Engl. v.18 Schmidt, H. J.;Schafer, H.
  18. Synthesis Olah, G. A.;Balaram Gupta, B. G.;Fung, A. P.
  19. J. Org. Chem. v.55 Nishiguchi, T.;Bougauchi, M.
  20. J. Org. Chem. v.54 Nishiguchi, T.;Bougauchi, M.
  21. J. Am. Chem. Soc. v.89 Deno, N. C.;Potter, N. H.
  22. Justus Liebigs Ann. Chem. v.47 Franzen, V.;Edens, R.
  23. J. Org. Chem. v.27 Pollart, K. A.;Miller, R. E.
  24. J. Am. Chem. Soc. v.91 Shono, T.;Matsunura, Y.
  25. Tetrahedron Lett. v.23 Oku, A.;Harada, T.;Kita, K.
  26. Tetrahedron Lett. v.24 Barua, N. C.;Sharma, R. P.;Baruab, J. N.
  27. Synthesis Olah, G. A.;Ho, T. L.
  28. J. Org. Chem. v.42 Ho, T. L.;Olah, G. A.
  29. Synthesis Olah, G. A.;Welch, J.
  30. J. Am. Chem. Soc. v.98 Ogawa, T.;Matsui, M.
  31. J. Am. Chem. Soc. v.98 Jung, M. E.;Speltz, L. M.
  32. Angew. Chem. Int. Ed. Engl. v.17 Schmidt, W.;Steckhan, W.
  33. J. Am. Chem. Soc. v.105 Semmelhack, M. F.;Chous, C. S.;Cortes D. A.
  34. Tetrahedron Lett. v.29 Yamahuchi, M.;Takata, T.;Endo, T.
  35. J. Org. Chem. v.55 Yamahuchi, M.;Takata, T.;Endo, T.
  36. Heterocycles v.27 Bobbitt, J. M.;Flores, M. C. L.
  37. Tetrahedton Lett. v.27 Semmelhach, M. F.;Schmid, C. R.;Cortes, D. A.
  38. J. Org. Chem. v.50 Miyazawa, T.;Endo, T.;Shiigashi, S.;Okawara, M.
  39. J. Am. Chem. Soc. v.105 Semmelhack, M. F.;Chou, C. S.;Cortes, D. A.
  40. J. Org. Chem. v.50 Miyazawa, T.;Endo, T.
  41. J. Am. Chem. Soc. v.106 Endo, T.;Miyazawa, T.;Shiihashi, S.;Okawara, M.
  42. J. Tetrahedron Lett. v.25 Hunter, D. H.;Barton, D. H. R.;Motherwell, W.
  43. J. Am. Chem. Soc. v.105 Semmelhack, M. F.;Schmid, C. R.
  44. J. Org. Chem. v.53 Hunter, D. H.;Racok, J. S.;Rey, A. W.;Ponce, Y. Z.
  45. Heterocycles v.30 Bobbitt, J. M.;Flores, M. C. G.;Ma, Z.;Tang, H.
  46. J. Korean Chem. Soc. v.38 Cho, N. S.;Kim, Y. H.
  47. J. Molecular Catalysis v.31 Miyazawa, T.;Endo, T.
  48. J. Molecular Catalysis v.32 Miyazawa, T.;Endo, T.
  49. J. Org. Chem. v.52 Anelli, P. L.;Biffi, C.;Montanari, F.;Quici, S.
  50. J. Org. Chem. v.54 Anelli, P. L.;Banfi, S.;Montanari, F.;Quici, S.
  51. J. Org. Chem. v.55 Inokuchi, T.;Matsumoto, S.;Nishiyama, T.;Torii, S.
  52. Tetrahedron Lett. v.31 Siedlecka, R.;Skarzewski, J.;Mlochowski, J.
  53. J. Am. Chem. Soc. v.106 Semmelhack, M. F.;Schmid, C. R.;Cortes, D. A.;Chou, C. S.
  54. J. Org. Chem. v.56 Ma, Z.;Bobbitt, J. M.
  55. Tetrahedron Lett. v.27 Miyazawa, T.;Endo, T.
  56. J. Am. Chem. Soc. v.102 Boyd, J. W.;Schmalzl, P. W.;Miller, L. L.
  57. Bull. Korean Chem. Soc. v.15 Cho, N. S.;Park, C. H.
  58. J. Org. Chem. v.46 Bal. B. S.;Kochhar, K. S.;Pinnick, H. W.
  59. J. Am. Chem. Soc. v.105 Forouni, H. E.;Kriahman, S.;Kuhn, D. G.;Hamilton, G. A.