Dispersion forces in chirality recognition – a density functional and wave function theory study of diols

Abstract

In the discussion of chirality recognition, steric considerations and strongly directed interactions such as hydrogen bonds are primarily discussed. However, given the sheer size of biomolecules, it is expected that...

Recognition in the Domain of Molecular Chirality: From Noncovalent Interactions to Separation of Enantiomers

“…78,320,641 Recently, Mata et al explored the impact of dispersive forces in chiral recognition during the formation of homochiral/heterochiral dimers of small diols, showing that dispersive forces are crucial for the manifestation of chiral recognition. 642 For this purpose, dispersion contributions were "'turned on and off"' for both DFT and WFT methods by using proper dispersion-correction in order to see how both the energy and structure of the systems were affected by dispersive forces. On the other hand, in most cases directionality has proven to be an important requirement for enantioselection.…”

“…From this perspective, in the last few decades, classification, comprehension, and quantification of noncovalent interactions have provided new approaches for performing and rationalizing enantioselective recognition processes. In principle, all noncovalent interactions may act enantioselectively, contributing to enantiorecognition processes, not only classical HB, π–π stacking, and dipole–dipole interactions, but even those considered to be nondirectional, such as steric, dispersive, and hydrophobic contacts, with the latter being of substantial relevance in aqueous and hydro-organic eluents. ,, Recently, Mata et al explored the impact of dispersive forces in chiral recognition during the formation of homochiral/heterochiral dimers of small diols, showing that dispersive forces are crucial for the manifestation of chiral recognition . For this purpose, dispersion contributions were “‘turned on and off”’ for both DFT and WFT methods by using proper dispersion-correction in order to see how both the energy and structure of the systems were affected by dispersive forces.…”

“…While a huge number of studies have been performed in the field of asymmetric HB-based catalysis, , there are very few studies on XB-based asymmetric catalysis. ,, The question of XB-based catalysis is that this interaction has a divergent character with respect to the relative position of the chiral backbone bearing the halogen and the substrate as XB acceptor, given XB directionality with a C–X···acceptor angle tending to the reference value of 180°. Thus, with the aim to engineer the interaction in an exploitable manner, it is necessary that XB converges toward a chiral confined space which, in principle, may accommodate substrate and reagents involved in the catalytic process.…”

Deployment of Sulfinimines in Charge-Accelerated Sulfonium Rearrangement Enables a Surrogate Asymmetric Mannich Reaction

“…In order to deconvolute the underlying reasons for this stability, we conducted an additional computational investigation. Encouraged by recent studies emphasizing the importance of dispersion interactions for the enantioselectivity of organocatalytic processes, , we tested the role of these effects for geometry optimization of both transition states, TS-2 E and TS-2 Z , comparing results of the B3LYP-D3­(BJ) and the B3LYP (without dispersion correction) DFT approaches. Indeed, if dispersion is neglected, a substantial structural distortion is observed for TS-2 Z , while for TS-2 E , the effect is less significant (SI, S70, Table S3).…”

“…Aiming to pinpoint the intricacies of this unprecedented process, we adopted a combined experimental/computational approach. Subjecting an 18 O-labeled amide to the standard conditions led to exclusive formation of nonlabeled product, suggesting that the sulfinimine acts as oxygen donor (SI, S66). 16 Our quantum chemical calculations (Scheme 3), based on precedent and the observations described above, assumed initial formation of a keteniminium intermediate A (Scheme 3A), 17 which was used as the starting point.…”