Sugar hemiacetals were smoothly transformed into the corresponding glycosyl bromides by treatment with carbon tetrabromide in N,N-dimethylformamide with tris(2,2′-bipyridyl)ruthenium(II) chloride as a catalyst under visible-light irradiation. Protecting groups commonly used in carbohydrate derivatives are unaffected by the mild conditions for bromination.
Key words
carbohydrates - halogenation - bromine - photochemistry - catalysis - ruthenium