Kinetics and mechanism of the oxidative regeneration of carbonyl compoundsfrom oximes by tetrabutylammonium tribromide

The oxidative deoximination of several aldo- and keto-oximes by tetrabutyla mmonium tribromide (TBAT) in 1:1 (v/v) acetic acid-water exhibits a first o rder dependence on each the oxime and TBAT. The oxidation of ketoximes is s lower than that of aldoximes. The rates of oxidation of aldoximes correlate well in terms of Pavelich-Taft dual substituent-parameter equation. The lo w positive value of polar reaction constant indicates a nucleophilic attack by a tribromide ion on the carbonyl carbon. The reaction is subject to ste ric hindrance by the alkyl groups. A mechanism involving the formation of a cyclic activated complex in the rate-determining step has been proposed.