The Synthesis of C-linked Glycosides

Recent Advances in Transition Metal-Catalyzed Glycosylation

“…C -Glycosides are an important class of biologically active compounds. − They are of particular interest because of their resistance to metabolic processing, making them viable drug candidates and competitive inhibitors of processing enzymes. − Although catalytic approaches to C -glycosides are somewhat rare, there are numerous methods available for constructing the anomeric carbon–carbon bond, in which generation of electrophilic, nucleophilic, or radical character is observed at C(1); however, most of these approaches rely on substrate control to provide selectivity in the reaction. Cross-coupling reactions are an obvious approach to C -glycosides; however, fully oxygenated and saturated structures are usually not attainable through such methods because of the susceptibility of C(1)-substituted metal complex to undergo β-hydride or alkoxy elimination.…”

A Room Temperature Negishi Cross-Coupling Approach to C-Alkyl Glycosides

“…C-Glycosides represent an important class of bioactive compounds that are resistant to metabolic processing. , Although cross-coupling reactions are obvious approaches to these compounds, the sensitivity of C1-substituted organometallics to β-elimination processes (hydride or alkoxy) is the generally accepted reason why fully oxygenated and saturated structures are not typically accessible via these methods. − This notion is generally true of the synthetic methods that generate nucleophilic character at C1 . The contrastingly high number of methods for the synthesis of 2-deoxy C-glycosides 2a reinforces the notion of an elimination problem in C1 organometallics …”

Multigram Synthesis of Isobutyl-β-C-galactoside as a Substitute of Isopropylthiogalactoside for Exogenous Gene Induction in Mammalian Cells

“…Obviously key to any successful synthesis of IBCG is the method for installation of the C -glycoside. Stereoselective formation of C -glycosidic bonds have attracted significant attentions in the recent years. , Among methods for the synthesis of β- C- glycosides, the one-step condensation between free sugars in aqueous solutions and 2,4-pentanedione was particularly attractive as a way to quickly make β- C -glycosidic ketones without prior protection of the carbohydrate hydroxyl groups . A mixture of C -glycoside stereoisomers are formed in the initial Knoevenagel condensation; however, extended heating under basic conditions allow the equilibrium to shift to the β- C -glycosidic pyranose ketone (Scheme ) .…”