A theoretical study on diastereoselective oxidative dearomatization by iodoxybenzoic acid

Abstract

The reaction mechanism of diastereoselective oxidative dearomatization by iodoxybenzoic acid of key compounds involved in the total synthesis of epicocconone analogs, which are efficient fluorophores with a wide range of applications in protein staining and separation, was studied using density functional theory. In particular, the conformational space was investigated, as was the role of the so-called hypervalent twist move, which is thought to be the rate-determining step. Both kinetic and thermodynamical aspects of the mechanism were considered from static and dynamic viewpoints, including solvent effects. The results were then rationalized using conceptual density functional theory and Bader's atoms-in-molecules framework, which demonstrated how complementary these two approaches are when studying organic chemistry reactions theoretically.

Towards the first theoretical scale of the trans effect in octahedral complexes

“…Both STE and KTE are frequently epitomised by square planar complexes, with a d 8 electronic configuration of the metal cation, 5 and octahedral complexes, with either a d 6 or d 0 metal electronic configuration. 6 More rarely, they can be observed for lanthanide, 7 actinide 8,9 or even iodine 10,11 complexes. These two effects are known to be a likely cause of several chemical properties, ranging from catalytic activity and selectivity [12][13][14] to metalloprotein reactivity [15][16][17][18] and anti-tumoral activity.…”

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

“…A hypervalent twist, defined as coordinated motion of an oxo group and an anionic ligand, is thus necessary to generate a stable intermediate ( 8 ) and is followed by reductive elimination involving cleavage of the C–H bond. Goddard’s work concluded that the hypervalent twist is the RDS, and this prediction has influenced subsequent research. ,− However, it is known that the exchange between the apical and the equatorial ligands is an easy process in both λ 3 - and λ 5 -iodanes . More importantly, the hypervalent twist does not involve C–H bond cleavage, and this seems inconsistent with Corey’s KIE experiment.…”

Revisiting the effect of f‐functions in predicting the right reaction mechanism for hypervalent iodine reagents

“…17 Same conclusion has been drawn later by other researchers using various functionals with basis sets similar to LACV3P**. [18][19][20][21] However, this conclusion is inconsistent with the Corey's kinetic isotope effect (KIE) experiments. 22 In 2017, our theoretical study employing a wide range of basis sets at the level of both DFT and density cumulant theory (DCT) revealed that the RDS of IBX-mediated oxidation is strongly sensitive to the choice of basis sets.…”

“…Earlier density functional theory (DFT) study 15 determined the hypervalent twist as the RDS using the MPW1K functional and the LACV3P** basis set, 16 which is a combination of Pople's 6‐311G** basis set 14 and the LANL2DZ effective core 17 . Same conclusion has been drawn later by other researchers using various functionals with basis sets similar to LACV3P** 18–21 . However, this conclusion is inconsistent with the Corey's kinetic isotope effect (KIE) experiments 22 …”