Introduction of Structural Diversity at the C2 Position of Unsaturated Iminosugars through Palladium‐Catalyzed Cross‐Coupling Reactions

To increase the structural diversity of iminosugars at the C2 position, protected 2-iodoiminoglycals, efficiently synthesized from sugar lactams, are subjected to mild palladium-catalyzed cross-coupling reactions. Successful aminocarbonylation, arylation, and phosphonylation provide a range of C2-functionalized iminoglycals, which, once O-deprotected, are tested as glycosidase inhibitors.

To vary the functionality of iminosugars at the C2 position, protected 2-iodoiminoglycals in the D-gluco, D-galacto, and D-xylo series are efficiently synthesized from sugar lactams. Their mild palladium-catalyzed aminocarbonylation, arylation, and phosphonylation are successful and provide a range of C2-functionalized iminoglycals in good yields. Two of these compounds are O-deprotected to afford 1,2-unsaturated iminosugars that prove to be modest inhibitors of glycosidases.