Fundamentals of chirality, resolution, and enantiopure molecule synthesis methods

Abstract

The chirality of molecules is a concept that explains the interactions in nature. We may observe the same formula but different organizations revolving around the chiral center. Since Pasteur's meticulous observation of sodium ammonium tartrate crystals' structure, scientists have discovered many features of chiral molecules. The number of newly approved single enantiomeric drugs increases every year and takes place in the market. Thus, separation or resolution methods of racemic mixtures are of continued importance in the efficacy of drugs, installation of affordable production processes, and convenient synthetic chemistry practice. This article presents the asymmetric synthesis approaches and the classification of direct resolution methods of chiral molecules.

An electrochemical sensor based on metal–organic framework–chiral ionic liquid composites for the enantiorecognition of tryptophan enantiomers

“…In recent years, d -amino acids have been found in mammals and reported to be associated with the development and progress of some diseases. 1–7 For example, l -Trp is an essential amino acid in the human body, which is involved in the synthesis of biological proteins and the regulation of metabolic networks. l -Trp dysregulation may cause nervous system dysfunction, whereas, d -Trp almost does not participate in the metabolic process of organisms.…”

Resolving phenylephrine HCl and guaifenesin enantiomers on cellulose‐based chiral stationary phases: Separation of four enantiomers on 50‐mm column

“…The presence of this atomic center in a molecule makes it present in two mirror‐imaging forms, which are commonly called enantiomers. The two enantiomers could be present together in an equimolar ratio, and thus, the sample is optically inactive and identified as a racemic mixture 1 . On the other hand, the pharmacological activity is usually attributed to one enantiomer; whereas, the other optical isomer could possess equal or different activity.…”

“…It could also show diminished or detrimental activity with a toxic side effect 2 . This diversion is attributed to the chiral selectivity behavior of biological receptors 1 . For instance, phenylephrine HCl (PHE) is a phenethylamine‐type α1‐adrenergic receptor agonist with vasoconstriction activity to relieve nasal congestion 3 .…”

“…The two enantiomers could be present together in an equimolar ratio, and thus, the sample is optically inactive and identified as a racemic mixture. 1 On the other hand, the pharmacological activity is usually attributed to one enantiomer; whereas, the other optical isomer could possess equal or different activity. It could also show diminished or detrimental activity with a toxic side effect.…”

Probing the chirality and optical activity of organic molecules through the anisotropic photoluminescence of porous silicon

“…2 The identification and synthesis of chiral molecules are more challenging than the identification and synthesis of nonchiral molecules. 3,4 Traditional spectroscopic techniques are insufficient for distinguishing the asymmetry of chiral molecules; thus, more advanced techniques are required to distinguish this asymmetry. 5,6 Research on chiral molecules is critical because of their potential applications in diverse fields, including pharmaceuticals, 7 catalysts, 8 and optoelectronic materials.…”