title: Application and mechanistic studies of a water-oxidation catalyst in alcohol oxidation by employing oxygen-transfer reagents.
abstract: By using a dimeric ruthenium complex in combination with tert-butyl hydrogen peroxide (TBHP) as stoichiometric oxidant, a mild and efficient protocol for the oxidation of secondary benzylic alcohols was obtained, thereby giving the corresponding ketones in high yields within 4 h. However, in the oxidation of aliphatic alcohols, the TBHP protocol suffered from low conversions owing to a competing Ru-catalyzed disproportionation of the oxidant. Gratifyingly, by switching to Oxone (2 KHSO(5)⋅KHSO(4)⋅K(2)SO(4) triple salt) as stoichiometric oxidant, a more efficient and robust system was obtained that allowed for the oxidation of a wide range of aliphatic and benzylic secondary alcohols, giving the corresponding ketones in excellent yields. The mechanism for these reactions is believed to involve a high-valent Ru(V)-oxo species. We provide support for such an intermediate by means of mechanistic studies.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Sweden.
authors.forename: Oscar
authors.initials: O
authors.lastname: Verho
authors.forename: Marléne D V
authors.initials: MD
authors.lastname: Dilenstam
authors.forename: Markus D
authors.initials: MD
authors.lastname: Kärkäs
authors.forename: Eric V
authors.initials: EV
authors.lastname: Johnston
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Akermark
authors.forename: Jan-E
authors.initials: JE
authors.lastname: Bäckvall
authors.forename: Björn
authors.initials: B
authors.lastname: Akermark