Electrochemical Oxidation of Benzoins to Benzils in the Presence of a Catalytic Amount of KI in Basic Media

Abstract

Various benzoins were transformed into the corresponding benzils via an electrochemical method. Although the strategy of oxidizing benzoins to the corresponding benzils is generally chosen depending on the nature of the aromatic moiety, the electrochemical technique reported herein allows oxidation that is widely applicable, and without the use of environmentally undesirable oxidants.

Key words

alcohols - ketones - dehydrogenations - iodine - electron transfer

References

• 1a Vollhardt KPC. Schore NE. Organic Chemistry   2nd ed.:  Freeman; New York: 1994.  p.924-929  
• 1b Smith LI. Hoehn HH. Org. Synth., Coll. Vol. III   Wiley; New York: 1955.  p.356 
• 1c Johnson JR. Grummitt O. Org. Synth., Coll. Vol. III   Wiley; New York: 1955.  p.806 
• 1d Cope AC. Smith DS. Cotter RJ. Org. Synth., Coll. Vol. IV   Wiley; New York: 1963.  p.377 
• 1e Vofsi D. Asscher M. Org. Synth., Coll. Vol. V   Wiley; New York: 1973.  p.1076 
• 1f Morrison H. Danishefsky S. Yates P. J. Org. Chem.  1961,  26:  2617 
• 2 Weiss M. Apple M. J. Am. Chem. Soc.  1948,  70:  3666 
• 3 Clarke HT. Dreger EE. Org. Synth., Coll. Vol. I   Wiley; New York: 1941.  p.87 
• 4 Cainelli G. Cardillo G. Chromium Oxidants in Organic Chemistry   Springer; Berlin: 1984. 
• 5a Iranpoor N. Firouzabadi H. Zolfigol MA. Bull. Chem. Soc. Jpn.  1998,  71:  905 
• 5b Tymonko SA. Nattier BA. Mohan RS. Tetrahedron Lett.  1999,  40:  7657 
• 5c Sharma VB. Jain SL. Sain B. Tetrahedron Lett.  2003,  44:  383 
• 5d Firouzabadi H. Mohammadpour-Baltork I. Bull. Chem. Soc. Jpn.  1992,  65:  1131 
• 5e Mahjoub AR. Ghammami S. Kassaee MZ. Tetrahedron Lett.  2003,  44:  4555 
• 5f Firouzabadi H. Iranpoor N. Amani K. Synthesis  2003,  408 
• 5g Bhar S. Chaudhuri SK. Tetrahedron  2003,  59:  3493 
• 5h Mitsumoto Y. Nitta M. Bull. Chem. Soc. Jpn.  2003,  76:  1029 
• 5i Shirini F. Tajik H. Aliakbar A. Akbar A. Synth. Commun.  2001,  31:  767 
• 5j Khandekar AC. Paul AM. Khadikar BM. Synth. Commun.  2002,  32:  2931 
• 6a Mandal SK. Jensen DR. Pugsley JS. Sigman MS. J. Org. Chem.  2003,  68:  4600 
• 6b Velusamy S. Punniyamurthy T. Org. Lett.  2004,  6:  217 
• 6c Chang S. Lee M. Ko S. Lee PH. Synth. Commun.  2002,  32:  1279 
• 7 For example, see: Torii S. Electroorganic Synthesis   Kodansha; Tokyo: 1985. 
• 8a Chiba T. Saitoh I. Okimoto M. J. Org. Chem.  1999,  64:  2516 
• 8b Chiba T. Saitoh I. Okimoto M. Synthesis  1999,  1022 
• 8c Okimoto M. Takahashi Y. Bull. Chem. Soc. Jpn.  2002,  75:  2059 
• 8d Okimoto M. Takahashi Y. Synthesis  2002,  2215 
• 8e Okimoto M. Takahashi Y. Kakuchi T. Synthesis  2003,  2257 
• 8f Okimoto M. Nagata Y. Sueda S. Takahashi Y. Synth. Commun.  2004,  34:  281 
• 9 Beilsteins Handbuch der Organischen Chemie   4th ed.:  Springer; Berlin: 1943. 
• 10 Ide WS. Buck JS. Org. React.  1949,  4:  269