C-Glycoside Clustering on Calix[4]arene,Adamantane,and Benzene Scaffolds through 1,2,3-Triazole Linkers

摘要

A route has been paved toward the preparation of triazole glycocluster libraries via the copper(I)-catalyzed modern version of the classical Huisgen 1,3-dipolar cycloaddition of azides to alkynes.Up to four 1,4-disubstituted 1,2,3-triazole rings bearing carbon-linked glycosyl fragments were constructed on various scaffolds via multiple cycloadditions of suitably polyfunctionalized calix[4]arene,adamantane,and benzene derivatives with ethynyl and azidomethyl C-glycosides.Each cycloaddition occurred with high regio-selectivity to give exclusively the 1,4-disubstituted triazole ring in very high yield up to an average value of 98%.The high degree of efficiency of this approach and its wide scope constitute a simple and practical means for the attachment of various sugar units to polyfunctionalized substrates.