18724-29-3Relevant academic research and scientific papers
Pyridinium Chlorochromate Releases Quinones from Hydroquinone Silyl Ethers.
Willis, John P.,Gogins, Kitty A.,Miller, Larry L.
, p. 3215 - 3218 (2007/10/02)
The pyridinium chlorochromate oxidation of six bis(trimethylsilyl) and six bis(tert-butyldimethylsilyl) ethers of p-hydroquinones at room temperature in methylene chloride solution gave the corresponding quinones in 60-90percent yield.The bis(trimethylsilyl) ethers were slightly more reactive than the bis(tert-butyldimethylsilyl) ethers.High oxidation efficiency was indicated by a 1:1 molar stoichiometry; however, more convenient reaction times were obtained at a 2:1 molar ratio of pyridinium chlorochromate (PCC) to hydroquinone silyl ether.The mechanism is discussed based upon comparisons of relative reaction rates with electrochemical oxidation potentials.
Oxidation of Hydroquinone Silyl Esters to Quinones
Stewart, Ray F.,Miller, Larry L.
, p. 4999 - 5004 (2007/10/02)
The electrochemical oxidation of trialkylsiloxybenzene derivatives was investigated using platinum and graphite anodes in either acetonitrile or methylene chloride solvent.Preparative oxidation of the bis(trimethylsilyl) ethers of hydroquinone, chlorohydroquinone, 2,5-di-tert-butylhydroquinone, and 9,10-dihydroxyanthracene gave the corresponding quinones in 80-90percent yield.Oxidation of 1,4-bis(trimethylsiloxy)-2-methoxybenzene in acetonitrile gave 3,6-dihydroxy-2,7-dimethoxydibenzofuran in 65percent yield.Oxidation of 1-methoxy-4-(trimethylsiloxy)benzene in methanolic acetonitrile produced 1,1-dimethoxy-2,5-cyclohexadien-4-one in 99percent yield.The cyclic voltammograms of the trimethylsilyl, triethylsilyl, and tert-butyldimethylsilyl ethers of 2,5-di-tert-butylhydroquinone were recorded using acetonitrile and methylene chloride solvents at 25 and -60 deg C.These compounds were found to react by initial one-electron oxidation to generate a cation radical which decomposes by silicon-oxygen bond cleavage to eventually form quinone.The relative rates for decomposition of the trimethylsilyl, triethylsilyl, and tert-butyldimethylsilyl ether cation radicals at -60 deg C were 10:5:1. tert-Butyldimethylsilyl chloride and tert-butyldimethylsilyl triflate were found to be stable toward cathodic reduction in dry methylene chloride and acetonitrile at potentials as negative as -2.1 vs.Ag/0.1 M AgNO3.Cyclic voltammetry indicated that reduction of 2,5-di-tert-butylbenzoquinone, anthraquinone, and naphthoquinone in the presence of tert-butyldimethylsilyl chloride resulted in reductive silylation.
