Imine-based chiroptical sensing for analysis of chiral amines: from method design to synthetic application

Abstract

A robust chiroptical method for fast enantiopurity determination of chiral amines utilizing HPLC-CD, applied to monitoring crude transamination reactions.

Stereochemical analysis of chiral amines, diamines, and amino alcohols: Practical chiroptical sensing based on dynamic covalent chemistry

“…[13][14][15][16][17][18] Their outstanding work has spurred the development of a wide variety of CD sensor designs by Borhan, [19][20][21] Canary, 22,23 Anslyn, [24][25][26][27] our group, [28][29][30][31][32][33][34][35][36][37][38] and others. [39][40][41][42][43] The large majority of CD sensing assays introduced so far relies on the formation of supramolecular assemblies, metal coordination complexes, hydrogen bond adducts, or dynamic covalent chemistry (DCC). 12 In addition, stereodynamic probes that undergo irreversible covalent [This article is part of the Special Issue: In honor and memory of Prof. Koji Nakanishi.…”

“…[44][45][46][47][48][49][50][51][52] Nevertheless, reversible Schiff base formation with chiral amines has become a very popular and highly successful CD sensing strategy. 27,28,30,39,41,53,54 We now wish to report a highly practical method that allows chiroptical ee analysis of a wide range of amines and amino alcohols using an inexpensive commercially available benzaldehyde derivative as probe. The Schiff base formation is complete within 2.5 hours at room temperature and does not require operation under inert atmosphere, which greatly streamlines the workflow and would simplify automation of the assay and parallel handling of samples if desired.…”

Deviations from Beer's law in electronic absorption and circular dichroism: Detection for enantiomeric excess analysis

“…One is to determine the concentration of each enantiomer after chiral separation . The other is to measure the enantiomeric excess (ee) with a circular dichroism (CD) detector . The combination of achiral high‐performance liquid chromatography (HPLC) separation and CD detection has shown advantages in chiral analysis .…”

“…[1][2][3][4][5][6][7] The other is to measure the enantiomeric excess (ee) with a circular dichroism (CD) detector. [8][9][10][11] The combination of achiral high-performance liquid chromatography (HPLC) separation and CD detection has shown advantages in chiral analysis. 12 For instance, an achiral HPLC-CD system can be used for ee measurements without chiral separation and thus shortens the time required for analysis.…”

Chirality Sensing With Stereodynamic Biphenolate Zinc Complexes

“…The chiral amplification process and sensing response can then be exploited for qualitative and quantitative stereochemical analysis of the bound substrate. [16][17][18][19][20] Seminal progress with the development of a variety of chiroptical chemosensors and powerful chirality sensing assays that can be used for the determination of the absolute configuration and enantiomeric excess (ee) of many compounds has been made by Berova and Nakanishi, [21][22][23][24] Anslyn, [25][26][27][28][29] Canary, 30, 31 Joyce, 32 and Borhan. The covalent attachment of a chiral amino acid, carboxylic acid, amine, or alcohol was found to effectively disturb the racemic equilibrium of the biphenyl conformations in the probe, thus inducing spontaneous chirality amplification.…”