Synthesis of readily modifiable cyclodextrin analogues via cyclodimerization of an alkynyl-azido trisaccharide.

A convergent strategy for the synthesis of beta-cyclodextrin analogues is reported, utilizing preferential cyclodimerization of an azido-alkyne trisaccharide via Cu(I)-catalyzed [3 + 2] dipolar cycloaddition of the alkyne and azide functional groups. The resultant oligosaccharide macrocycle retains the binding propensity of cyclodextrins, as demonstrated by the similar ANS association constants measured for macrocycle 1 and beta-cyclodextrin. This new synthetic strategy opens up new avenues for modular preparation of functionally diverse cyclodextrin analogues that are otherwise inaccessible.