Enantiopure 1,4,5-Trisubstituted 1,2,3-Triazoles from Carbohydrates: Applications of Organoselenium Chemistry

A wide range of stable vinyl selenone-modified
furanosides has
been synthesized for the first time. These 2π-partners undergo
1,3-dipolar cycloaddition reactions with a wide range of organic azides
to afford enantiopure trisubstituted triazoles. Furanosyl rings opened
up during triazole synthesis to generate polyfunctionalized molecules,
ready to undergo further transformations. This strategy is one of
the most convenient methods for the synthesis of enantiopure 1,4,5-trisubstituted
1,2,3-triazoles where the chiral components are attached to C-4 or
C-5 position of triazole ring. These triazoles are formed in a regioselective
manner, and several pairs of regioisomeric triazoles have also been
synthesized. The approach affords densely functionalized triazoles,
which are amenable to further modifications because of the presence
of aldehyde and hydroxyl groups. This powerful and practical route
adds to the arsenals of chemists and biologists interested in the
synthesis and applications of triazoles.