Elemental Iodine or Diphenyl Diselenide in the [Bis(trifluoroacetoxy)iodo]benzene-Mediated Conversion of Alkynes into 1,2-Diketones

Both elemental iodine and diphenyl diselenides, in the presence of [bis(trifluoroacetoxy)iodo]benzene (FIFA), promote the transformation of internal alkynes into the corresponding 1,2-diketones. The reactions carried out in the presence of iodine unfortunately did not proceed with complete conversion of the starting alkynes. On the other hand, diphenyl diselenide was more efficient and gave satisfactory transformation of the starting alkynes into 1,2-diketones in better yields. The structure of the vicinal dicarbonyl compounds were confirmed by applying a subsequent condensation reaction to construct the corresponding quinoxaline derivatives.