Chiral Recognition of In Situ-Oxidized Phosphine Oxides with Octahedral Indium Complexes by ³¹P NMR Spectroscopy

Abstract

Herein, efficient chiral recognition of phosphine oxides with octahedral indium complexes was demonstrated. Direct chiral analysis of in situ-prepared phosphine oxides formed using phosphines and hydrogen peroxide was conducted effectively via 31P nuclear magnetic resonance spectroscopy. Sufficient peak resolution of chiral phosphines was obtained consistently, thereby enabling the reliable determination of absolute chirality. Rational 1:1 binding models based on experiments and density functional theory calculations have been proposed.

Enantiospecific Analysis of Carboxylic Acids Using Cinchona Alkaloid Dimers as Chiral Solvating Agents

“…The design of novel CSAs for the discrimination of enantiomers has been very crucial and imperative for prochiral analytes and has gained significant attraction. Various types of small organic molecular guests for chiral recognition of carboxylic acids, amino acids, alcohols, amines, and metabonomics applications have been developed and synthesized, including chiral thioureas, − amino alcohols, − chiral macrocyclic/crown ethers, − metal pincer complexes, − amide-derived atropisomers, etc. These CSAs with extensive hydrogen bonding sites have proven to be versatile shift reagents, allowing 1 H NMR based discrimination of a range of chiral compounds.…”

Chiral Discrimination of Monosaccharides Derivatized with 2-Fluorophenyl Hydrazine Using 19F NMR Spectroscopy

“…In this study, a simple yet effective chiral analysis method was developed for 15 aldose sugars by combining 2-fluorophenyl hydrazone derivatization with the utilization of octahedral chiral gallium ([Ga]­Na) and scandium ([Sc]­Na) complexes. − Unlike other approaches that necessitate optically pure reagents for sugar derivatization, this method utilizes 2-fluorophenyl hydrazine and chiral shift reagents. The high-yielding synthesis of sugar hydrazones without any side products facilitated efficient identification and differentiation of sugar enantiomers using 19 F NMR spectroscopy. ,,− This method offers both quantitative and qualitative analyses, the advantages of a broad analysis window, and the absence of background signals in 19 F NMR spectroscopy.…”