Stereochemistry and Recent Applications of Axially Chiral Organic Molecules

Abstract

This minireview covers the literature of the last decade related to the stereochemistry of axially chiral molecules. The first section reviews the use of dynamic NMR and dynamic HPLC for the ranking of the steric size of common organic moieties. The second and third sections describe the recent advances in the preparation of new atropisomeric scaffolds, and in the asymmetric synthesis of stereogenic axes by means of atroposelective organocatalysis.

Recent advances in the applications of pyrazolone derivatives in enantioselective synthesis

“…The enantioselective construction of atropoisomeric heterocyclic structures has attracted great attention in the organic community in recent years. 13 The Li group disclosed the first example of the synthesis of axially chiral pyrazole derivatives 18 from pyrazolones 1 (Scheme 3). 14 Utilizing the excellent reactivity of azonaphthalenes 17 , which were first described by Tan, 13 b a wide range of axially chiral pyrazole derivatives 18 was obtained in good yields with excellent enantioselectivities in the presence of the chiral phosphoric acid C7 as the catalyst.…”

Atroposelective Synthesis, Structure and Properties of a Novel Class of Axially Chiral N‐Aryl Quinolinium Salt

“…The latter has attracted attention due to their leishmanicidal properties, while the oxidized form ancischeynine has been synthesized racemically and spectroscopically resolved [5,6] . Recently the pharmaceutical importance of N ‐aryl atropisomers has been highlighted; [7–10] examples include sedative and recreational drug methaqualone, and AMG 510, a first‐in‐class KRAS inhibitor and potent anti‐tumour agent recently reported by Amgen [11] . The synthesis of heterobiaryl atropisomers is less‐developed than the all‐carbon variants, though some effective strategies have been reported [12–16] .…”

4,15-Dimethyl-7,12-diazoniatricyclo[10.4.0.02,7]hexadeca-1(12),2,4,6,13,15-hexaene dibromide monohydrate

“…There are no unusual bond lengths or angles. As a result of the two bridges between the pyridine rings, 1 occurs as two optical isomers, and therefore provides an example of atropisomerism (Eliel et al, 1994;Alkorta et al, 2012;Mancinelli et al, 2020). Crystals of 1, however, were centrosymmetric, with space group P2 1 /n, and are thus strictly racemic.…”