Chirality sensing of choline derivatives by a triple anion helicate cage through induced circular dichroism

Abstract

Chirality sensing of choline derivatives is achieved by a self-assembled, racemic triple anion helicate cage which exhibits induced circular dichroism (ICD) upon encapsulation of a chiral guest. The host-guest interactions were illustrated by NMR, crystal structure, CD and DFT calculations. The absolute configurations and ee values were determined by ICD.

Selective recognition of choline phosphate by tripodal hexa-urea receptors with dual binding sites: crystal and solution evidence

“…The tripodal hexa-urea L 1 (Scheme 1)13 and related ligands14 display efficient coordination with the divalent sulfate ion. Recently, the triple anion helicate formed from a bis–bis(urea) ligand with a methylene-diphenylene spacer was found to exhibit an ‘aromatic box’ that can selectively bind choline and its derivatives 15. Therefore, we reasoned that the hexa-urea moiety with aromatic terminal groups may provide the necessary dual binding sites for the anionic choline phosphate.…”

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

“…[7] Host-guest chemistry is an alternative method to expand the substrate scope of CD-based chiroptical sensing.F or example,B iedermann and Nau [8] have reported that the complexes of cucurbit [8]uril with dicationic dyes can be applied in chiroptical sensing of av ariety of biological molecules and drug molecules in water. This strategy is general in terms of functional groups but limited to molecules with an aromatic group next to their chiral centers.A cyclic cucurbit[n]urils and molecular tweezers, [9] pillar[n]arenes, [10] calix[n]arene, [11] resorcinarene, [12] covalent cage molecules, [13] foldamers, [14] and helicates [15] with aromatic sidewalls have also been demonstrated as chirality sensors.But the guests are still limited to aromatic compounds,c harged organic compounds,o rr igid molecules.M olecular sensors with aw ide substrate scope still remain to be developed for optical chirality sensing.…”

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

“…This strategy is general in terms of functional groups but limited to molecules with an aromatic group next to their chiral centers. Acyclic cucurbit[ n ]urils and molecular tweezers, [9] pillar[ n ]arenes, [10] calix[ n ]arene, [11] resorcinarene, [12] covalent cage molecules, [13] foldamers, [14] and helicates [15] with aromatic sidewalls have also been demonstrated as chirality sensors. But the guests are still limited to aromatic compounds, charged organic compounds, or rigid molecules.…”