Selective Oxidation of Uracil and Adenine Derivatives by the Catalytic System MeReO3/H2O2 and MeReO3/Urea Hydrogen Peroxide

Methyltrioxorhenium (MTO) is a useful and selective catalyst for the oxidation of uracil and purine derivatives using environmentally friendly hydrogen peroxide (H2O2, 30% water solution) or hydrogen peroxide/urea adduct (UHP) as oxygen atom donors. In particular, the MTO/UHP system constitutes a convenient combination to convert uracil derivatives into the biologically relevant 5,6-oxiranyl-5,6-dihydrouracils in good yields. Purine derivatives are selectively oxidized to the corresponding 1-oxides, the best yield being obtained in the presence of pyrazine-2-carboxylic acid (PCA). The oxidation of the plasmid pBG1 is also reported as the first example of double-strand DNA cleavage mediated by the catalytic system MTO/H2O2.