AuBr₃-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

Abstract

Herein we report, for the first time, the successful anomeric azidation of per-O-acetylated and per-O-benzoylated sugars by catalytic amounts of oxophilic AuBr3 in good to excellent yields. The method is applicable to a wide range of easily accessible per-O-acetylated and per-O-benzoylated sugars. While reaction with per-O-acetylated and per-O-benzoylated monosaccharides was complete within 1–3 h at room temperature, the per-O-benzoylated disaccharides needed 2–3 h of heating at 55 °C.

A Direct Brønsted Acid‐Catalyzed Azidation of Benzhydrols and Carbohydrates

“…2,3,4,6‐Tetra‐ O ‐acetyl‐β‐D‐galactopyranosyl Azide (3c): The title compound was prepared from 1,2,3,4,6‐penta‐O‐acetyl‐β‐D‐galactopyranose. Purification by flash chromatography using 50 % ethyl acetate in hexanes afforded 3c as a pale yellow oil.…”

Synthesis of N-glycosyl amides: conformational analysis and evaluation as inhibitors of β-galactosidase from E. coli

“…13 2,3,4,6-Tetra-O-acetyl-b-D-galactopyranosyl-1-azide (5b). [27][28][29][50][51][52][53] Following the general procedure, glycosyl azide 5b was obtained as a white solid. M.p.…”

Relevant Advances in the Synthesis and Applications of N‐Glycopyranosides

“…The reaction was completed by providing the compound 2,3,4,6‐tetra ‐O ‐acetyl‐β‐D‐glucopyranosyl azide ( 70 ) in 91 % yield (Scheme 17). [51} According to the authors, [51] the reaction was realized in the absence of molecular sieves and there was no formation of lactols as by‐products. This simple protocol enables the synthesis of various N ‐glycoconjugates offering a wide range of applications and further demonstrating the importance of gold catalysis in carbohydrate chemistry.…”