Design and preparation of a polymer resin-supported organoselenium catalyst with industrial potential

Hexavalent Se? Yes! Selenium on polymers exhibits quite different properties compared to that in small molecules. Hexavalent Se, rare in organoselenium chemistry, was found to be the major species on polymers. The high-valent Se species on recyclable polymer resins could quickly catalyze the oxidation reaction of cyclohexene with H2O2 in water to produce industrially important intermediate trans-1,2-cyclohexanediol in almost quantitative yield. In the catalytic cycle, high valent Se species were reduced to divalent Se, a highly activated species that could be re-oxidized by air so that no excess H2O2 was required for the reaction. The results were superior to those of reactions catalyzed by small molecules, for which excess H2O2, long reaction time or expensive CF3-activated catalysts and environmentally unfriendly MeCN solvent were required.