Monatshefte f€ ur Chemie 134, 1571–1575 (2003) DOI 10.1007/s00706-003-0073-6 An Efficient and Selective Solid State Oxidation of Thiols to Disulfides with Quinolinium Fluorochromate on Silica Gel Mahmood Tajbakhsh 1; , Iraj Mohammadpoor-Baltork 2 , and Kamal Alimohammadi 1 1 Department of Chemistry, Mazandaran University, Babolsar, Iran 2 Department of Chemistry, Isfahan University, Isfahan, Iran Received April 28, 2003; accepted (revised) May 15, 2003 Published online October 20, 2003 # Springer-Verlag 2003 Summary. Various kinds of aliphatic (cyclic and acyclic), aromatic, and heterocyclic thiols are con- verted into the corresponding disulfides by quinolinium fluorochromate (QFC) on silica-gel in excel- lent yields. Selective oxidation of thiols in the presence of sulfides is also achieved under solid phase conditions. Keywords. Quinolinium fluorochromate; Thiols; Oxidations; Chemoselectivity; Solid state. Introduction Transformation of thiols to disulfides is important from both synthetic and bio- chemical points of view, and accordingly, numerous studies have been reported [1– 15]. This conversion has been accomplished using a variety of reagents such as molecular oxygen [2], metal ions [3], metal oxides [3a], DMSO [4], nitric oxide [5], halogens [6], sodium perborate [7], electrochemical oxidation [8], clayfen [9], borohydride exchange resin transition metal salt systems [10], morpholine iodine complex [11], pyridinium chlorochromate [12], aqueous HIO 3 [13], ammonium persulfate [14], Caro’s acid supported on silica-gel [15], and horseradish perox- idase or mushroom tyrosinase [16]. Most of the reagents involve solvents in pro- tocols that lack the general applicability to thiol substrates bearing alkyl, aryl, and heterocyclic moieties. There is increasing emphasis on technological developments for reactions proceeding in the absence of solvent [17] or utilizing mechano- chemical techniques [18]. Recently, we have reported several chromium(VI) based  Corresponding author. E-mail: tajbaksh@umz.ac.ir