Multicomponent Approach to Homo- and Hetero-Multivalent Glycomimetics Bearing Rare Monosaccharides

摘要

We applied a multicomponent approach to access a library of densely functionalized homo- and hetero-multivalent glycomimetics comprising aldehyde, amine, and isocyanide components related to isopropylidene-protected D-fructose, L-sorbose, D-galactose, and D-allose. Passerini products were obtained in very good yields (up to 78%) and high diastereoselectivities (up to 98:2). Three types of products were obtained by the Ugi reaction; along with the "classical" four-component product, alpha-acylaminoamides, a three-component alpha-aminoamides, and a four- component alpha-aminoacylamides were isolated. The presence of multiple pathways is rationalized by the structure of the imidate intermediate, mainly influenced by the amine component.