Selective modification of β-cyclodextrin: an unexpected tandem reaction enables the cross-linking of C2A and C2B via a sulfur atom

Abstract

2(A),3(A)-Alloepithio-2(B)-sulfonyl-beta-cyclodextrin undergoes a tandem reaction to generate an unprecedented C2(A)-S-C2(B)-bridged glucosyl-3(A),6(A)-anhydroglucoside segment.

Xylylene Clips for the Topology-Guided Control of the Inclusion and Self-Assembling Properties of Cyclodextrins

“…The above results confirm that whereas the o -xylylene bridge in 4 preserves the typical toroidal shape of βCD, the m -xylylene clip in 5 traps the elusive ovoid topology, a feature only observed previously in solution for βCD derivatives modified with anhydro bridges. − The semiopen conformation of 4 is, in principle, compatible with the inclusion of a variety of hydrophobic guests, with the only limitation imposed by the βCD cavity size. In the case of 5 , in spite of the fully open disposition of the aromatic ring, the inside-oriented O-2­(II) methyl substituent (black arrow in Figure ) partially blocks the cavity entrance.…”

Dynamic Control of the Self-Assembling Properties of Cyclodextrins by the Interplay of Aromatic and Host-Guest Interactions

“…Imposing distance restrictions in CDs through covalent bonds can lead to significant alterations in their primary structure, usually by provoking conformational changes in one or several of the monosaccharide building blocks, which may substantially perturb the inclusion capabilities (Fujita et al, 1988; Fukudome et al, 2007b; Álvarez-Dorta et al, 2015, 2016; Immel et al, 2001; Fukudome et al, 2007; León et al, 2018). Compounds 4 and 5 were purposely conceived to avoid this and keep the toroidal βCD cavity characteristic of βCD undistorted, so that any effect in their supramolecular properties can be ascribed to the presence of the naphthalene component, devoid from additional effects on the βCD macroring topology.…”