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Updated: Apr 11, 2026

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Chiral Recognition Studies of α-(Nonafluoro-tert-butoxy)carboxylic Acids by NMR Spectroscopy
Anikó Nemes1, Tamás Csóka1, Szabolcs Béni2,3
1†Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary.
Abstract:
Three chiral α-(nonafluoro-tert-butoxy)carboxylic acids (R)-1, (RS)-2, (R)-3 were synthesized to examine their application as chiral solvating agents with amines. As a model compound, first (S)- and/or (RS)-α-phenylethylamine was used, and their diastereomeric salts were investigated by (1)H and (19)F NMR and ECD spectroscopy. The NMR spectroscopic studies were carried out at room temperature using the slightly polar CDCl3 and apolar C6D6 as solvents in 5 mM and 54 mM concentrations. The difference of the chemical shifts (Δδ) in the diastereomeric complexes is comparable with other, well-known chiral derivatizing and solvating agents (e.g., Mosher's acid, Pirkle's alcohol). Diastereomeric salts of racemic acids (RS)-1 and (RS)-2 with biologically active amines (1R,2S)-ephedrine and (S)-dapoxetine were also investigated by (19)F NMR spectroscopy.
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