UNUSUALLY LARGE KINETIC DEUTERIUM ISOTOPE EFFECTS ON OXIDATION REACTIONS. 1. THE MECHANISM OF HYDROXIDE-CATALYSED PERMANGANATE OXIDATION OF PhCD(CF3)OH AND PhCD(CH3)OH IN WATER

Article abstract of DOI:10.1002/poc.610080309

The oxidation of 1-phenyl-2,2,-trifluoroethanol (ROH) with potassium permanganate in 0.2 M aqueous sodium hydroxide solution at 25 deg C provides 2,2,2-trifluoroacetophenone as the sole product.The reaction rate constant, which was measured under pseudo-first order conditions by following the decrease in substrate concentration as a function of time, was found to be substantially smaller than previously reported.The primary kinetic deuterium isotope effect was measured as k₂^H/k₂^D= 14.7 +/- 1.0.A hydrogen-transfer mechanism involving significant tunnelling is proposed.The oxidation of 1-phenylethanol under similar reaction conditions yields acetophenone as the initial product.The kinetic deuterium isotope effect was found to be k₂^H/k₂^D = 5.2 +/- 0.8.