Photooxidation of thiosaccharides mediated by sensitizers in aerobic and environmentally friendly conditions

A series of β-d-glucopyranosyl derivates have been synthesized and evaluated in photooxidation reactions promoted by visible light and mediated by organic dyes under aerobic conditions. Among the different photocatalysts employed, tetra-O-acetyl riboflavin afforded chemoselectively the respective sulfoxides, without over-oxidation to sulfones, in good to excellent yields and short reaction times. This new methodology for the preparation of synthetically useful glycosyl sulfoxides constitutes a catalytic, efficient, economical, and environmentally friendly oxidation process not reported so far for carbohydrates.

An environmentally friendly and simple sensitized photooxidation methodology to obtain glycosyl sulfoxides with outstanding chemoselectivity in aerobic conditions is described.