New approach to C-aryl glycosides starting from phenol and glycosyl fluoride. Lewis acid-catalyzed rearrangement of O-glycoside to C-glycoside

In vitro characterization of IroB, a pathogen-associated C -glycosyltransferase

“…During elaboration of the natural products listed above and in IroB catalysis, the acceptor cosubstrate is an electron-rich phenol ring. In the angucyclines and granaticin, the observation that the glycosylated carbon is ortho to the phenol oxygen has raised the question of whether the reaction sequence consists of (i) O-glycosylation followed by a nonenzy-matic O 3 C glycosyl migration (42) or (ii) direct C-glycosylation.…”

C-Nucleosides Derived from Simple Aromatic Hydrocarbons

“…The major product of this reaction was a sugar ketal which arose from attack of the metallophenyl species on the C-2' ester carbonyl. Matsumoto and coworkers 21 accomplished the synthesis of β-D-ribofuranosyl derivative (13) of 2-naphthol by C-glycosylation of 2-naphthol with the furanosyl fluoride (12) in the presence of a catalytic amount of Cp 2 HfCl 2 -AgClO 4 (Fig.2C). The α:β-anomeric ratio for this reaction was found to be 1:9.…”

Synthesis of 3‐Deoxy Glycals via Tandem Metathesis Sequences and Their Use in an Intermolecular Heck Arylation

“…[56][57][58][59] A classical method for obtaining C-aryl glycosides involves an O-glycosylation of phenols with glycosyl fluorides, followed by a Fries-type OǞC rearrangement. [60] Palladium-mediated couplings of a 3-pyranoid glycal with aryl iodides (Heck reaction) [61] or an organomercury compound leading to a C-aryl glycoside have been reported by Daves and co-workers. [62] A major obstacle in these intermolecular Heck arylations of cyclic enol ethers is the occasionally low reactivity, resulting in long reaction times at elevated temperatures, high catalyst loadings and the necessity to use one coupling partner in excess.…”