A theoretical investigation of the competition between hydrogen bonding and lone pair⋯π interaction in complexes of TNT with NH3

Exploiting non-covalent π interactions for catalyst design

“…However, several studies, both theoretical 83–85 and experimental, have noted the shortcomings of this picture and acknowledge the likely significance of electron correlation, or dispersion effects, with weak attractive interactions having been observed for electron-rich aromatic systems with negative quadrupole moments 86 . Although it is expected to be individually quite weak, the significance of the lp–π interaction has been noted in cooperation with other NCIs such as hydrogen-bonding (see below) 87,88 . The first lp–π interaction to be acknowledged explicitly originates in structural biology as a stabilizing structural element for Z-DNA 89,90 .…”

Atypical Lone Pair–π Interaction with Quinone Methides in a Series of Imido‐Ferrociphenol Anticancer Drug Candidates

“…[3a] Functionalization of the alkyl chain of 1 by attaching aterminal hydroxy substituent [4] or aheterocyclic group, [5] as in 3 or 4,resulted in extremely low IC 50 values (0.035 mm)on TNBC MDA-MB-231 cells;m oreover,f or the epithelial ovarian cancer cell line A2780 and the cisplatin-resistant species A2780cisR, the IC 50 values were 0.035 and 0.049 mm, respectively.T he first metabolite obtained either in the chemical (Ag + )o re nzymatic oxidation of 1 in cancer cells is the quinone methide 1-QM (Figure 1a), which can react in a1 ,8-Michael addition with selective nucleophiles in the cancer cells. [10] Thes trength and nature of lp-p interactions have been elucidated in only af ew studies, [11] mostly on simplified binding systems of two small molecules, [12] or in rigid structures. First invoked in 1995 for the stabilization of Z-DNA, [7] it is now widely recognised as anew supramolecular bond.…”

“…First invoked in 1995 for the stabilization of Z-DNA, [7] it is now widely recognised as anew supramolecular bond. [10] Thes trength and nature of lp-p interactions have been elucidated in only af ew studies, [11] mostly on simplified binding systems of two small molecules, [12] or in rigid structures. [10] Thes trength and nature of lp-p interactions have been elucidated in only af ew studies, [11] mostly on simplified binding systems of two small molecules, [12] or in rigid structures.…”

“…[8] Although perhaps counterintuitive,a nd rather weak, it has been invoked in biological macromolecules [9] and host-guest systems. [10] Thes trength and nature of lp-p interactions have been elucidated in only af ew studies, [11] mostly on simplified binding systems of two small molecules, [12] or in rigid structures. [13] There are also few virtual applications in medicinal chemistry or organocatalysis.…”

Enantiodivergent Fluorination of Allylic Alcohols: Data Set Design Reveals Structural Interplay between Achiral Directing Group and Chiral Anion

“…On the basis of the following observations, we propose that a lone pair-π interaction − (Figure C) is attenuating enantioselectivity: (1) our experiments isolated the interaction to an alkoxy group at a specific position of the aryl BA, (2) variation of this alkoxy group resulted in drastically altered selectivity, and (3) subtle changes to the catalyst aryl ring had a considerable impact on enantioselectivity. First discovered as a stabilizing element for the conformation of Z-DNA (Figure C), the lone pair-π interaction entails an overlap between a heteroatom lone pair and the face of an aromatic ring, and has been demonstrated to be highly dependent on the geometries of both interacting partners .…”