Organic selenoxides as oxidants in osmium tetroxide catalyzed oxidation of olefins to glycols

✍ Scribed by A.G. Abatjoglou; D.R. Bryant

• Publisher: Elsevier Science
• Year: 1981
• Tongue: French
• Weight: 218 KB
• Volume: 22
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)93274-5

✦ Synopsis

Olefins are catalytically oxidized to glycols by osmium tetroxide in the presence of organic selenoxide cooxidants. Glycols were obtained in good yields from mono-, di-, tri-and tetrasubstituted olefins. Osmium tetroxide is widely used as a catalyst for the cis-dihydroxylation of olefins in conjunction with stoichiometric cooxidants such as hydrogen peroxide, metal chlorates, and t-butyl hydroperoxide (1). Oxygen as a stoichiometric oxidant in osmium tetroxide catalyzed dihydroxylation of olefins has been patented (2), but apparently low reaction rates and rapid catalyst deactivation diminish the practical utility of the method. We report on our investigation of novel homogeneous, liquid phase, olefin oxidation systems composed of osmium, cooxidant, and oxygen. The cooxidant cycles the reduced osmium catalyst and the cooxidant, in turn, is recyclable with oxygen. We found that organic selenoxides are effective cooxidants in osmium tetroxide catalyzed olefin to glycol reactions. Alkaline solutions of diphenyl-and phenylmethyl selenoxide in alkaline aqueous acetone, oxidize soluble osmium (VI) to osmium (VIII).

The selenoxide is cleanly reduced to the selenide (Eq. 1). tetroxide R2Se0 + 0~0; + H20 -> R2Se + 0s04(OH); Alkaline solutions of the two selenoxides containing catalytic quantities of osmium are stable over a period of hours. When they are combined with a variety of olefins,