Cyclodextrins selectively modified on both rims using an O-3-debenzylative post-functionalisation, a consequence of the Sorrento meeting

Cyclodextrin-based multivalent glycodisplays: covalent and supramolecular conjugates to assess carbohydrate–protein interactions

“…The inner nanometric cavity of the cyclooligosaccharide core, comparatively hydrophobic, remains essentially unaltered after conjugation, preserving the distinct inclusion capabilities of CDs already profusely exploited by the pharmaceutical industry for drug encapsulation purposes. [28][29][30][31][32][33] Multivalent CDs can be thus considered as hybrid ligand-host molecules bearing two orthogonal recognition domains, namely the glycoligand display and the hydrophobic cavity. The potential of such unique arrangement for receptor-mediated site-specific delivery of active guests or probes was soon recognized and has been a permanent motivation for the design and optimization of multivalent CD conjugates.…”

Direct and Regioselective Di‐α‐fucosylation on the Secondary Rim of β‐Cyclodextrin

“…The synthesis of the acceptors started with perbenzylationo fc ommerciallya vailable a-a nd b-CD, providing the protected CDs 1 and 2 in high yield (Scheme 2). [29] These were then subjected to Et 3 SiH/I 2 [39,40] to regioselectively liberate all C-3 hydroxyls to give acceptors 3 and 4,having six and seven free hydroxyls, respectively.F or the a-fucosylation of these acceptors, reported thio-fucoside donor 5 was utilized (Scheme 3). While the stereoselectivei ntroduction of multiple a-fucosidic bonds simultaneously remains ac hallenging endeavor,t his donorh as provent op rovide robust a-fucosylation in other glycan syntheses.…”

“…The synthesis of the acceptors started with perbenzylation of commercially available α‐ and β‐CD, providing the protected CDs 1 and 2 in high yield (Scheme ) . These were then subjected to Et 3 SiH/I 2 to regioselectively liberate all C‐3 hydroxyls to give acceptors 3 and 4 , having six and seven free hydroxyls, respectively. For the α‐fucosylation of these acceptors, reported thio‐fucoside donor 5 was utilized (Scheme ).…”

o-Xylylene Protecting Group in Carbohydrate Chemistry: Application to the Regioselective Protection of a Single vic-Diol Segment in Cyclodextrins

“…Position-selective functionalization of cyclodextrins is critical for the development of applications as sensors, , catalysts, − artificial enzymes, , or drug delivery systems among others. Most reported methods are limited to primary hydroxyls. ,− Only a few examples of the preparation of mono- and bifunctionalized CDs at the secondary rim have recently been reported. ,− In view of the results obtained on monosaccharide substrates, and considering that OH-2 is significantly more acidic than OH-3 and OH-6 and that the hydroxyls at the secondary CD rim are arranged in trans -diequatorial diol segments, the possibility of statistic o -xylylenation to access selectively O-2 I ,O-3 I -differentiated derivatives of the commercially available cyclomaltohexa- (αCD), -hepta- (βCD), and -octaose (γCD) seemed very appealing.…”