β‐Selective C‐Glycosylation and its Application in the Synthesis of Scleropentaside A

Abstract

C-Glycosides are carbohydrates that bear aC ÀC bond to an aglycon at the anomeric center.D ue to their high stability towardsc hemical and enzymatic hydrolysis,t hese compounds are widely used as carbohydrate mimics in drug development. Herein, we report ag eneral and exclusively bselective method for the synthesis of anaturally abundant acyl-C-glycosidic structural motif first found in the scleropentaside natural product family.ACorey-Seebachu mpolung reaction as the key step in the synthesis of scleropentaside Aa nd analogues enables the b-selective construction of the anomeric C À Cb ond starting from unprotected carbohydrates in only four steps.T he one-pot approach is highly atom-efficient and avoids the use of toxic heavy metals.

Diastereoselective Synthesis of Aryl C‐Glycosides from Glycosyl Esters via C−O Bond Homolysis

“…Cross‐coupling of glycosyl halides with organometalloarenes, [15] aromatic nucleophiles, [16] or aromatic electrophiles [17] achieved success with a range of carbohydrates, but 2‐deoxy sugar substrates, especially 2‐deoxyriboses, are susceptible to decomposition, due to the rapid elimination of glycosyl chlorides and bromides to form glycals [18] . Thus, many glycosyl halides often require in situ generation [19] . The Diels–Alder reaction is useful for preparing pyranoses, but cannot be applied to furanosides [20] .…”

Versatile Glycosyl Sulfonates in β‐Selective C‐Glycosylation

“…For instance, while the condensation of glucose with acetylacetone proceeds with excellent yield, similar reactions with aryl β‐diketones are much lower yielding . Alternatively, C‐acyl glycosides have been prepared through transition‐metal‐catalysed coupling, and Corey–Seebach reaction with excellent β‐selectivity (Scheme B). These approaches require an excess of heavy metals, or strongly oxidizing conditions to unmask the desired products.…”

Med Chem Remote: The Frontiers in Medicinal Chemistry 2021

“…He described a novel target‐based assay to screen for antagonists of the toll‐like receptors 7 and 8. After high throughput screening, the validated hits were optimized which led to a potent antagonist for TLR7/8 [29] …”