Issue
Korean Journal of Chemical Engineering,
Vol.31, No.3, 365-373, 2014
Electrochemical bromination and oxidation of alkyl aromatic compounds by two-phase electrolysis
A simple, regioselective, environmentally clean and economical method for the preparation of side chain/ring brominated aromatic compounds is reported in 70-98% yield by an electrochemical method using two phase electrolysis technique. Electrochemical reactions were carried out using aqueous 25-50 wt% sodium bromide containing catalytic amount (5 wt%) of hydrobromic acid as an aqueous phase and chloroform containing alkyl aromatic compounds as an organic phase, at a temperature of 0-30 oC in an undivided cell. The same two-phase electrolytic system can be used for the oxidation of benzylic alcohols to the corresponding benzaldehydes in 80-94% yield without over oxidation to carboxylic acids. The advantage of this very mild procedure is a room temperature reaction used with an undivided cell. Excellent conversions are observed. After completion of alcohol oxidation the electrolyte can be reused for a number of times, demonstrating “spent reagent” free electro organic reaction as an attractive one. In the case of side chain/ring bromination of alkyl aromatic compounds, the electrolyte can be reused after making up the concentration of the electrolyte with 47 wt% HBr solution. In some cases homogeneous electrolysis is applied, where the two-phase electrolysis did not work. Styrene epoxidation and α-bromination of ketones underwent homogeneous electrolysis at room temperature without any catalyst. The reaction was performed in CH3CN-water (3 : 2) using equimolar amount of NaBr as an electrolyte to get 68% of styrene epoxide. Use of an ionic liquid 1-butyl 3-methyl imidazolium bromide (Bmim) Br, instead of NaBr improved the yield and current efficiency of styrene epoxide to 86%.
[References]
  1. Shaikh TM, Sudalai A, Tetrahedron Lett., 46, 5587, 2005
  2. Eissen M, Lenoir D, Chem. Eng. J., 14, 9830, 2008
  3. Chakradhar A, Roopa R, Rajanna KC, Saiprakash PK, Synth. Commun., 39, 1817, 2009
  4. Mestres R, Palenzuela J, Green Chem., 4, 314, 2003
  5. Sperry JB, Wright DL, Chem. Soc. Rev., 35, 605, 2006
  6. Yoshida J, Kataoka K, Horcajada R, Nagaki A, Chem. Rev., 108(7), 2265, 2008
  7. Suga S, Matsumoto K, Ueoka K, Yoshida JI, J. Am. Chem. Soc., 128(24), 7710, 2006
  8. Forsyth SR, Pletcher D, Extended abstracts of Ist International Symposium on Electro organic synthesis, Kurashiki, 35, 1986
  9. Fees H, Wendt H, J. Chem. Technol. Biotechnol., 30, 297, 1980
  10. Morita M, Yamamoto S, Matsuda Y, J. Appl. Electrochem., 18, 49, 1988
  11. Raju T, Kulangiappar K, Kulandainathan MA, Shankar GK, Muthukumaran A, Electrochim. Acta, 51(2), 356, 2005
  12. Muthukumaran A, Raju T, Krishnan V, Bull. Electrochem., 9, 630, 1993
  13. Anbu Kulandainathan M, Kulangiappar K, Elangovan M, Govindu S, Raju T, Krishnan V, Bull. Electrochem., 16, 392, 2000
  14. Raju T, Kulangiappar K, Anbu Kulandainathan M, Revathy M, Uma U, Malini A, Tetrahedron Lett., 47, 4581, 2006
  15. Ogamino T, Mori K, Yamamura S, Nishiyama S, Electrochim. Acta, 49(27), 4865, 2004
  16. Rossen K, Volante RP, Reider PJ, Tetrahedron Lett., 38, 777, 1997
  17. N. H. Jonathan, A. Ahmed and H. S. Rodney, US Patent, 5,385,650. Jan 31, 1995
  18. Raju T, Kulangiappar K, Anbu Kulandainathan M, Tetrahedron Lett., 46, 7047, 2005
  19. Kulangiappar K, Karthick G, Anbu Kulandainathan M, Synth. Commun., 39, 2304, 2010
  20. Ullman’s encyclopedia of Industrial chemistry, 6th Ed., Wiley-VCH, Weinheim Electronic Release, 1998
  21. Butler A, Walker JV, Chem. Rev., 93, 1937, 1993
  22. Hudluchy M, Oxidations in organic chemistry, ACS Monograph series, American Chemical society, Washington, DC, 1990
  23. Stahl SS, Angew. Chem., Int. Ed., 43, 3400, 2004
  24. Cainelli G, Cardillo G, Chromium oxidants in organic chemistry, Springer, Berlin, 1984
  25. Musawir M, Davey PN, Kelly G, Kozhevnikov IV, Chem. Commun., 14, 14, 2003
  26. Jansson REW, Tomov NR, J. Appl. Electrochem., 10, 583, 1980
  27. Shimizu Y, Mitsudo K, Tanaka H, Tetrahedron Lett., 46, 8975, 2005
  28. Koo BS, Lee CK, Lee KJ, Synth. Commun., 32, 2115, 2002
  29. Yoshida T, Okimoto M, Hoshi M, Synth. Commun., 41, 3134, 2011
  30. Marco-Contelles J, Molina MT, Anjum S, Chem. Rev., 104(6), 2857, 2004
  31. Lane BS, Burgess K, Chem. Rev., 103(7), 2457, 2003
  32. Sakia I, Kashyap B, Phukan P, Synth. Commun., 40, 2647, 2010
  33. Raju T, Kulangiappar K, Unpublished results.
  34. Massuquinini I, Antunio JM, Ana P, Esteves DI, Maria JM, Comptes Rendus Chimie., 841, 2009
  35. Raju T, Kulangiappar K, Unpublished results.
  36. Erian AM, Sherif SM, Gaber HM, Molecules., 8, 793, 2003
  37. Giodano C, Castaldi G, Giordano C, JP92054657 - B2, 1992
  38. King LC,Ostrum Gk, J. Org. Chem.,, 29, 3459, 1964
  39. Khan AT, Goswami P, Choudhury LH, Tetrahedron Lett., 47, 2751, 2006
  40. Tanemura K, Suzuki T, Nishida Y, Satsumabayashi K, Horaguchi T, Chem. Lett., 32(10), 932, 2003
  41. Kajigaeshi S, Kakinami T, Okamoto T, Fujisaki S, Bull. Chem. Soc. Jpn., 60, 1159, 1987
  42. Senthil Kumar R, Kulangiappar K, Anbu Kulandainathan M, Synth. Commun., 40, 1736, 2010