Kinetics and mechanism of the oxidation of aliphatic alcohols by quinolinium fluorochromate

The oxidation of some aliphatic alcohols by quinolinium fluorochromate (QFC) in dimethyl sulfoxide leads to the formation of corresponding carbonyl compounds. The reaction is First order with respect to QFC. The reaction exhibited Michaelis-Menten type kinetics with respect to the alcohol. The reaction is catalyzed by hydrogen ions. The hydrogen-ion dependence has the form: k(obs) = a + b[H+]. The oxidation of [1,1-H-2(2)]ethanol (MeCD2OH) exhibits a substantial primary kinetic isotope effect. The reaction has been studied in nineteen different organic solvents. The solvent effect was analyzed using Taft's and Swain's multiparametric equations. The rate of disproportionation of the complex is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been proposed. (C) 1999 John Wiley & Sons, Inc.