A Twist of the Twist Mechanism, 2-Iodoxybenzoic Acid (IBX)-Mediated Oxidation of Alcohol Revisited: Theory and Experiment.

2-Iodoxybenzoic acid (IBX) is an important species for the oxidation of alcohols to aldehydes or ketones. An often-cited mechanism involving a hypervalent twist as the rate-determining step (RDS) is inconsistent with kinetic isotope effect (KIE) experiments. The computations with larger basis sets reveal that the reductive elimination involving the C-H bond cleavage is the RDS (rate-determining step). Further computational/experimental studies suggest that the reactivity can be improved by adjusting the trans influence with Lewis acids.