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The efficiency and scope of two acyclic π-wall extended cucurbiturils, M2 and M3 , exhibiting rapidly interconverting helical conformers for chiroptical sensing of amines, amino acids, alcohols, and terpenes at micromolar concentrations in water is evaluated. The formation of 1 : 1 host–guest complexes results in spontaneous induction of circular dichroism signals that can be used for accurate determination of the absolute configuration and enantiomeric composition of the analyte based on a simple mix-and-measure protocol. 

The efficiency and scope of two acyclic π-wall extended cucurbiturils, M2 and M3 , exhibiting rapidly interconverting helical conformers for chiroptical sensing of amines, amino acids, alcohols, and terpenes at micromolar concentrations in water is evaluated. The formation of 1 : 1 host–guest complexes results in spontaneous induction of circular dichroism signals that can be used for accurate determination of the absolute configuration and enantiomeric composition of the analyte based on a simple mix-and-measure protocol. 

Optical chirality sensing of unprotected amino acids, hydroxy acids, amino alcohols, amines and carboxylic acids based on a practical mix-and-measure protocol with readily available copper, iron, palladium, manganese, cerium or rhodium salts is demonstrated. The generation of strong cotton effects allows quantitative ee analysis of small sample amounts with high speed. In contrast to previously reported assays the use of chromophoric reporter ligands and the control of metal coordination kinetics and redox chemistry are not necessary which greatly simplifies the sensing procedure with the benefit of reduced waste production and cost. 

Abstract We have developed an optical method for accurate concentration,er, anddranalysis of amino alcohols based on a simple mix‐and‐measure workflow that is fully adaptable to multiwell plate technology and microscale analysis. The conversion of the four aminoindanol stereoisomers with salicylaldehyde to the corresponding Schiff base allows analysis of thedrbased on a change in the UV maximum at 420 nm that is very different for the homo‐ and heterochiral diastereomers and of the concentration of the sample using a hypsochromic shift of another absorption band around 340 nm that is independent of the analyte stereochemistry. Subsequent in situ formation of Cu^IIassemblies in the absence and presence of base enables quantification of theervalues for each diastereomeric pair by CD analysis. Applying a linear programming method and a parameter sweep algorithm, we determined the concentration and relative amounts of each of the four stereoisomers in 20 samples of vastly different stereoisomeric compositions with an averaged absolute percent error of 1.7 %. 

Abstract Broadly useful chiroptical enantiomeric excess (ee) sensing remains challenging and typically involves carefully designed molecular receptors or supramolecular assemblies. Herein, we report on the enantioselective sensing of 35 amino acids, amino phosphonic acids, hydroxy acids, amino alcohols, and diamines with an auxiliary‐free cobalt probe. Chiroptical analysis of the enantiomeric composition and concentration of minute sample amounts was achieved with high accuracy by using earth‐abundant cobalt salts and hydrogen peroxide as the oxidant. Despite the absence of an auxiliary ligand, the cobalt assay is applicable to aromatic and aliphatic compounds and yields strong CD signals at high wavelengths. This method obviates the general prerequisite for chromophoric metal ligands to generate chiroptical signals through ECCD (exciton‐coupled circular dichroism) effects or through analyte‐to‐ligand chirality induction, and it offers operational simplicity, cost efficiency, waste reduction, and speed.