A Green and Wide‐Scope Approach for Chiroptical Sensing of Organic Molecules through Biomimetic Recognition in Water

Abstract

Optical chirality sensing has attracted a lot of interest due to its potential in high‐throughput screening in chirality analysis. A molecular sensor is required to convert the chirality of analytes into optical signals. Although many molecular sensors have been reported, sensors with wide substrate scope remain to be developed. Herein, we report that the amide naphthotube‐based chirality sensors have an unprecedented wide scope for chiroptical sensing of organic molecules. The substrates include, but are not limited to common organic products in asymmetric catalysis, chiral molecules with inert groups or remote functional groups from their chiral centers, natural products and their derivatives, and chiral drugs. The effective chirality sensing is based on biomimetic recognition in water and on effective chirality transfer through guest‐induced formation of a chiral conformation of the sensors. Furthermore, the sensors can be used in real‐time monitoring on reaction kinetics in water and in determining absolute configurations and ee values of the products in asymmetric catalysis.

Chiroptical Enhancement of Chiral Dicarboxylic Acids from Confinement in a Stereodynamic Supramolecular Cage

“…has urged the development of fast and effective methods. Within this context, promising results have been reported by the use of supramolecular approaches which have developed molecular sensors able to amplify chiroptical signal intensities. − The leading strategy in this field is represented by the use of chemosensors carrying a chromophore unit and a labile stereogenic element in fast racemization. − Interaction of these stereodynamic probes with a chiral analyte shifts the equilibrium among the two enantiomeric forms of the receptor toward a preferential diastereoisomer. The presence of chromophores allows to translate this bias into a signal which is detected using electronic circular dichroism (CD).…”

Biomimetic Recognition and Optical Sensing of Carboxylic Acids in Water by Using a Buried Salt Bridge and the Hydrophobic Effect

“…Naphthotube 3a•6 HCl is achiral and has excellent binding affinities to carboxylic acids.T herefore,i ts hould be able to optically sense the chirality of chiral carboxylic acids. [21] As shown in Figures 5a and S108, induced CD spectra were indeed detected when adding chiral carboxylic acids 4b, 5b, or 7 into the solution of 3a•6 HCl or 3b•6 HCl in acetate buffer. In contrast, no obvious CD signals were induced when adding R-5b or R-7 into the aqueous or organic solutions of three organic cations with chromophores (Figures S109,S110), suggesting the macrocyclic structures of the naphthotubes are very important for effective chirality transfer.…”

When Molecules Meet in Water‐Recent Contributions of Supramolecular Chemistry to the Understanding of Molecular Recognition Processes in Water

“…The Jiang group subsequently demonstrated that naphthotubes bind a variety of polar guests in water, [185] including surrogates of nerve agents. [186] In addition, naphthotubes can be used for the chiroptical sensing of epoxides, alcohols, [187] and carboxylic acids, [92] and for the removal of micropollutants from water, rendering them potentially useful for practical applications. [188] Other macrocyclic tetralactams in which converging hydrogen bond donors and two hydrophobic anthracene units mediate guest binding in water are receptor 50 a, described by…”