Glycosamine Derivatives through Metal‐Catalyzed C−N Bond Formation on Protected and Unprotected 2‐Iodoglycals

Hirao Cross-Coupling Reaction as an Efficient Tool to Build Non-natural C2-Phosphonylated Sugars

A range of C2-phosphonylated sugars have been accessed through a palladium-catalyzed Hirao cross-coupling on 2-iodoglycals using trialkylphosphites as phosphorylating reagents. The developed conditions led to the creation of an unnatural C–P bond on sugars and proved to be compatible with diversely protected glycals (acetyl-, benzyl-, PMB-protected) as well as with unprotected substrates. Several monosaccharides and one disaccharide have been synthesized by applying this methodology. Deprotection conditions are also described.

Silicon-bridged (1→1)-disaccharides: an umpoled glycomimetic scaffold

Modification of the carbohydrate scaffold is an important theme in drug and vaccine discovery. Therefore, the preparation of novel types of glycomimetics is of interest in synthetic carbohydrate chemistry. In this manuscript, we present an early investigation of the synthesis, structure, and conformational behaviour of (1→1)-Si-disaccharides as a novel type of glycomimetics arising from the replacement of interglycosidic oxygen with a dimethyl-, methylpropyl-, or diisopropylsilyl linkage. We accomplished the preparation of this unusual group of umpoled compounds by the reaction of lithiated glycal or 2-oxyglycal units with dialkyldichlorosilanes. We demonstrated the good stability of the "Si-glycosidic" linkage under acidic conditions even at elevated temperatures. Next, we described the conformational landscape of these compounds by the combination of in silico modelling with spectroscopic and crystallographic methods. Finally, we explained the observed conformational flexibility of these compounds by the absence of gauche stabilizing effects that are typically at play in natural carbohydrates.

Sonogashira cross-coupling as a key step in the synthesis of new glycoporphyrins

Palladium catalysis is reported as an efficient tool to afford unique glycoporphyrins via Sonogashira cross-coupling.

Structure investigation on a novel 2-halo-2,3-unsaturated-N-galactoside, NMR and X-ray diffraction of a monoclinic multidomain crystal

Single crystal X-ray and NMR investigations on multidomain structured N-(4,6-di-O-acetyl-2,3-dideoxy-α-D-threo-hex-2-en-2-iodo-pyranosyl)-methylsulfonamide are reported. This is the first crystallographic diffraction data report related to a 2-halo-2,3-unsaturated galactoside derivative. A complete structural study, including conformations and crystal packing, was performed by analyzing the spectroscopic data in solid state (XRD) and in solution (NMR).