The mechanism of the Baeyer–Villiger rearrangement: quantum chemistry and TST study supported by experimental kinetic data

Abstract

The mechanism of the Baeyer-Villiger rearrangement is modelled for the reaction of propanone with trifluoroperacetic acid, catalyzed by trifluoroacetic acid in dichloromethane, using three DFT methods (B3LYP, BH&HLYP and MPWB1K) and MP2. These results are refined and used to calculate the overall reaction rate coefficient using conventional Transition State Theory. The excellent agreement between the calculated (1.00 x 10(-3) L mol(-1) s(-1)) and the experimental (1.8 x 10(-3) L mol(-1) s(-1)) rate coefficients at the MPWB1K level strongly supports the mechanism recently proposed by our group. This DFT method is then used to study the mechanism of a larger system: cyclohexanone + trifluoroperacetic acid, for which a very good agreement between the calculated and the experimental rate coefficients is also found (1.37 and 0.32 L mol(-1) s(-1), respectively). The modelled mechanism is not ionic but neutral, and consists of two concerted steps. The first one is strongly catalyzed while the second one, the migration step, seems not to be catalyzed for the systems under study. The results of this work could be of interest for understanding other reactions in non-polar solvents for which ionic mechanisms have been assumed.

A quantum chemical study on the free radical scavenging activity of tyrosol and hydroxytyrosol

“…These corrections are in good agreement with those independently obtained by Ardura et al [88] and have been successfully used by other authors [89][90][91].…”

Mechanistic Investigation of Chiral Phosphoric Acid Catalyzed Asymmetric Baeyer–Villiger Reaction of 3‐Substituted Cyclobutanones with H2O2 as the Oxidant

“…This reaction pathway is consistent with the kinetic results and the mechanistic proposal by List and Müller, [46] and it is similar to the mechanism of carboxylic acid catalyzed B-V oxidation using peracids proposed by Alvarez-Idaboy and co-workers. [19,22,23] Rationalization of the reactivities of different ketones towards the B-V reaction: The B-V reactions of acetone, cyclopentanone, and cyclohexanone were also examined theoretically, promoted by 1 c and using hydrogen peroxide as the oxidant. Because both the electrophilicity and hydrogen-bonding capability of these ketones can be expected to be similar to those of cyclobutanone, similar reactivity for the addition was assumed for both cyclic and acyclic ketones.…”

“…[3,[16][17][18] For the carbonyl addition step, there is still no consensus on whether the protonation of the carbonyl oxygen and the carbonyl addition occur in a stepwise or concerted manner. [19] Besides, there are some controversies with regards to the potential effect of the acid, which is generated as a byproduct during the reaction and may catalyze both steps. [18] Overall, the B-V reaction cannot be explained by a single mechanism and the detailed mechanism of the reaction varies with the catalyst, substituent effect, solvent, and/or acidity.…”

“…The multiple interaction mode for the activation of reactants disclosed in the reaction, that is, the catalyst with two different binding sites in close proximity, seems to be a common feature in several mechanistic models proposed for B-V reactions, and a close resemblance in mechanism can be found between the title reaction and catalysis by carboxylic acids, [19,22,23] metal ions, [25] or zeolites, [26] and thus may represent a promising approach for future catalyst development.…”

On the hydroperoxyl radical scavenging activity of two Edaravone derivatives: mechanism and kinetics

“…[66] These corrections are in good agreement with those independently obtained by Ardura et al [67] and have been successfully used by other authors. [68][69][70][71][72][73][74] The rate constants (k) were calculated using the conventional Transition State Theory (TST) [75][76][77] and 1 M standard state. Reaction path degeneracies, accounting for the number of equivalent reaction paths, and tunneling corrections have been included in the calculations.…”