Kinetics and mechanism of the oxidative regeneration of carbonyl compounds from oximes by pyridinium bromochromate

✍ Scribed by Pradeep K. Sharma

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 80 KB
• Volume: 38
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20185

✦ Synopsis

Abstract

The oxidative deoximination of several aldo‐ and keto‐oximes by pyridinium bromochromate (PBC), in dimethylsulfoxide, exhibited a first‐order dependence on both the reductant (oxime) and the oxidant (PBC). The oxidation of ketoximes is slower than that of aldoximes. The rates of oxidation of aldoximes correlated well in terms of the Pavelich–Taft dual substituent‐parameter equation. The low positive value of polar reaction constant indicated a nucleophilic attack by a chromate‐oxygen on the carbon. The reaction is subject to steric hindrance by the alkyl groups. The reaction of acetaldoxime has been studied in 19 different organic solvents. The solvent effect has been analyzed by Taft's and Swain's multiparametric equations. A mechanism involving the formation of a cyclic intermediate, in the rate‐determining step, has been proposed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 364–368, 2006