Base-free oxidation of thiols to disulfides using selenium ionic liquid

We present here the results on the use of 1-n-butyl-3-methylimidazolium methylselenite, [bmim] [SeO2(OCH3)], in the synthesis of symmetrical disulfides starting from thiols. This efficient and improved method is general for aromatic, aliphatic, and functionalized thiols affording the disulfides in good to excellent yields after easy work up. The use of a microwave accelerates the reaction and the [bmim] [SeO2(OCH3)] was reused for further oxidation reactions. (C) 2010 Elsevier Ltd. All rights reserved.