Preferential Recognition and Extraction to Pentoses over Hexoses by a D_6h-Symmetrical Ethynylphenol Macrocycle with Six Inner Phenolic Hydroxy Groups

Abstract

A macrocycle consisting of six ethynylphenol units was developed as a host architecture for saccharides. The rigid framework of the macrocycle suppressed the intramolecular hydrogen-bonding between adjacent phenolic hydroxy groups and recognized saccharides by intermolecular hydrogen-bonding within the hole. The well-defined hydrogen-bonding sites enabled the size-selective guest recognition and showed preference to pentoses over hexoses.

Synthesis of Rigid Macrocyclic Phenols and Their Catalytic Applications in Diels‐Alder Reactions

“…The reference compound 5 showed no signal change in the same titration with MVK , suggesting a significantly low affinity of 5 for MVK (Figure S3). This finding supports that the rigid macrocyclic framework enables the phenol‐acetylene‐phenol moiety to form efficient hydrogen bonds with a carbonyl group [7a] …”

“…In our previous work, [7a] the ethynylphenol macrocycle 3 was found to self‐assemble over the concentration of 1.0×10 −3 M. The strong self‐assembly of 3 has been presumed to be caused by intermolecular hydrogen bonds between hydroxy groups of the phenol rings. On the other hand, 4 a has fewer phenol rings, so that its self‐association is assumed to be weaker.…”

“…Very recently, we also reported that a shape‐persistent macrocyclic framework is suitable to suppress the intramolecular hydrogen bonds of phenol‐acetylene‐phenol moieties (Figure 1c) [7a] . An ethynylphenol macrocycle 3 did not form intramolecular hydrogen bonds because of its rigid cyclic framework, in which the acetylene bonds were hardly bent.…”

Fluorescent cyclophanes and their applications

“…Regarding those linked in meta positions, they were found to form nanostructured assemblies 171 and to have significant sensing properties. 172 p -Phenylene ethynylene cyclophanes—also named cyclo- para -phenylene-acetylenes—exhibit 173 a strong emissive behaviour and can lead to the generation of a rotaxane-like structure with single-walled carbon nanotubes. 174…”

Unprotected Galactosamine as a Dynamic Key for a Cyclochiral Lock

“…Among many other bioactive molecules, sugars and their derivatives constitute a class of compounds whose discrimination and sensing are particularly challenging, especially in water where host−guest interactions compete with solvation phenomena. Different efforts have very recently been devoted to discriminating between saccharides; pentoses have been extracted over hexose 17 and their homo-and heterodimers were recognized through self-assembled double helical foldamers, 18 non-all-equatorial saccharides were selected by "synthetic lectins", 19 oligosaccharides were distinguished by probing their length and building block compositions through specific nanoparticles, 20 and β-glucoside was used as a reference carbohydrate for a series of synthetic receptors. 21 Our research efforts, aimed at exploiting a highly directional noncovalent network to select saccharides, have been applied herein to their amino derivatives.…”