Ruthenium (VIII) mediated oxidation of some aliphatic and alicyclic ketones by periodate-ruthenium (III) system in aqueous HClO4 medium

✍ Scribed by Markandeswar Panda; Subas C. Pati

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 477 KB
• Volume: 28
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1996)28:6<453::aid-kin7>3.0.co;2-u

✦ Synopsis

The kinetics of Ruthenium( Ill) chloride mediated oxidation of acetone, 2-butanone, 4-methyl-2-pentanone, 2-pentanone, cyclopentanone, and cyclohexanone by sodium periodate in aqueous HCIO, media was zero-order in I lo,-) and first-order in I ketone]. The reaction was independent of added I R u ( l l 1 ) J and showed first-order dependence on [H+] for all the ketones studied, except acetone. In the case of acetone at I H +I < 0 05 M , the rate was independent of I H ' I, the order in IRu(1ll)J being unity; but at IH'] > 0.05 M the reaction showed unit dependence on IH'I and the order in I R u ( 1 l l ) J was zero Ruthenium(VI11) generated in situ is postulated as the hydride abstracting species A mechanism involving enolization as the rate determining step is proposed. Acetone at lower acidity of the medium is shown to react directly with Ru(VIII). In the absence of ruthenium(l1l) chloride, the kinetics were first-order in

I

.I, I ketone], and I H + I . Structure-reactivity relationship is discussed and thermodynamic parameters are reported.