GPx-Like Activity of Selenides and Selenoxides: Experimental Evidence for the Involvement of Hydroxy Perhydroxy Selenane as the Active Species

Abstract

The reaction mechanism of the GPx-like oxidation of PhSH with H(2)O(2) catalyzed by selenoxides proceeds via formation of the hydroxy perhydroxy selenane, which is a stronger oxidizing agent than selenoxide. A hydroxy perhydroxy selenane intermediate was observed by electrospray ionization mass spectrometry and (77)Se NMR spectroscopy in reactions of selenoxide 8 with H(2)O(2).The initial velocity of oxidation of PhSH by H(2)O(2) with selenoxide 8 is 4 orders of magnitude higher than that of 8 without peroxide. Selenoxide 8 is not reduced to selenide 6 by PhSH in the presence of H(2)O(2). While electronic substituent effects have minimal impact on the catalytic performance of selenoxides, chelating groups increase the rate of catalysis.

Synthesis, characterization, structures and GPx mimicking activity of pyridyl and pyrimidyl based organoselenium compounds

“…There was hardly any activity for Ph 2 Se whereas the corresponding heterocyclic derivatives 2a and 2b were active under similar conditions; the 2a being more active. The observed activity in 2 could be due to stabilization of the proposed thioselenurane, R 2 Se(OH)(SR 0 ), intermediate species [20,22,53] through heterocyclic N/H secondary interactions.…”

Microwave-assisted one-pot synthesis of symmetrical diselenides, ditellurides and disulfides from organoyl iodides and elemental chalcogen catalyzed by CuO nanoparticles

“…However, on using all of these catalysts a decline in the yield was observed (entries [6][7][8]. It is notable that in the absence of the catalyst in the reaction the product was not observed (entry 9).…”

“…Over the past few decades organochalcogen compounds have attracted considerable attention due to their importance as reagents and synthetic intermediates in organic synthesis [1][2][3][4][5][6]. Several types of these compounds play a crucial role in biology and biochemistry.…”

Copper-Catalyzed Three-Component One-Pot Synthesis of Substituted 2-Aryl-1,3-benzoselenazoles

“…1,10-Phenanthroline ligand was tested for acceleration of the reaction, but the results indicated no significant yields improvement (Table 1, entry 6 vs. 7). Base and solvent screening revealed that KOH was optimal and DMSO was the most suitable (Table 1, entries [13][14][15][16]. Interesting, when the solvent changed to toluene (Table 1, entry 16), not any product was obtained.…”