Chiral recognition of tartaric acid derivatives with chromenone-benzoxazole receptors and a spirobifluorene spacer

Chiral Binol–Bisboronic Acid as Fluorescence Sensor for Sugar Acids

“…[2,14,15] Boronic-acid-based fluorescence sensors for tartaric acid, [32] d-glucuronate, [33,34] and d-glucarate [35] have been reported, as has a boronic-acidbased colorimetric indicator-displacement assay for the determination of the enantiomeric excess of a-hydroxy acids. [36] Hydrogen-bonding receptors for the binding of tartaric acid [37] and the chiral discrimination of hydroxy carboxylates [38] and tartaric acid [39,40] are also known. In order to develop improved fluorescent chiral discriminating systems, we investigated the interaction of the two chiral forms of sensor 1 (R and S) with a range of sugar acids over a range of pH values.…”

Chiral Recognition of Carboxylates—Receptors, Analytical Tools, and More

“…TLC analysis, in which a racemic mixture of the receptor is subjected to chromatography on a plate that is impregnated with a homochiral guest (Figure ), is another method worth mentioning. This approach, successfully used by Morán's group, is quite simple and offers a good throughput, yet it provides only a semiquantitative comparison, as there is no direct correlation between the R f values and α.…”

Synthesis and Properties of Annulated 2-(Azaar-2-yl)- and 2,2'-Di(azaar-2-yl)-9,9'-spirobifluorenes

“…303.65 °C. 6,6',7,9'-spirobi(fluoreno [2,3-c]acridine) (7a). A mixture of ketone 5 (226 mg, 0.50 mmol) and 2-aminobenzaldehyde (4a, 133 mg, 2.20 mmol) in absolute EtOH (20 mL) containing saturated alcoholic KOH (1 mL) was refluxed for 5 h. Upon cooling the reaction mixture, the solid was formed, which was collected as a pure pale yellow crystalline solid (82%): m.p.…”

“…9,9'-Spirobifluorene (1) as well as its derivatives have been of interest due to their characteristic structures [1], of which the early studies were focused not only on the molecular recognition of various α-aminoalcohols by 9,9'-spirobifluorene-based crown ethers [2,3] and of monosaccharides by dendritic cleft receptors [4][5][6], but also on the inclusion of compounds with hydrocarbons [7], carbohydrates [8,9], and α-hydroxycarboxylates [10]. However, interest in 9,9'-spirobifluorenes, especially 9,9'-spirobifluorenebased oligomers, as well as polymers has recently switched to applications in molecular electronic devices for light emitting devices [11][12][13][14][15][16], hybrid porous solid [17] and catalysis [18].…”