Reaction of Glycals with Organic Peroxides: Synthesis of 2-iodo, 2-Deoxy and 2,3-Unsaturated Glycosides

Abstract

Reaction of peroxides with glycals, when carried in the presence of NIS affords2‐deoxy‐2‐iodo‐α‐glycosides in good yields with predominant trans‐diaxial selectivity at rt. Under photolytic conditions in the presence of catalytic eosin Y, the reaction leads to 2‐deoxyglycosides or 2,3‐unsaturated‐α‐glycosides. NIS plays two roles firstly, to form an iodonium ion with the glycal and secondly to bring about the decomposition of the organic peroxide into an alcohol that reacts with the activated sugar whereas blue LED light and Eosin Y bring about a radical‐mediated glycosylation to give the α‐2‐deoxy glycoside or 2,3‐unsaturated glycosides based on the protecting group at C‐3 position of glycals.

Transformations of carbohydrate derivatives enabled by photocatalysis and visible light photochemistry

“…Mukherjee and co-workers showed that 2-deoxy- O -glycosides can be synthesized from glycals by a related approach involving the addition an alkoxy radical to the 1-position, followed by hydrogen atom transfer to the C2-centered radical. 109 The transformation was achieved using tert -butyl hydroperoxide as the alkoxy radical precursor and Eosin Y as photocatalyst.…”

Recent Advances and Development in Visible‐Light‐Mediated Glycosylation: An Expanding Research Area in Glycochemistry

“…Later on, Mukherjee and co-workers reported a novel route to synthesis the 2-deoxy and 2,3-unsaturated glycosides through a photo-catalyzed system (Scheme 36). [103] The merger of tri-O-benzyl-D-glycal with TBHP in CH 3 CN and using eco-friendly organic dye, eosin Y (1 mol%) under blue LED, afforded 2- Further ahead, a noteworthy example was published recently by wang and co-workers focusing on trichloroacetimidates substrates en route to O-glycosides in good to excellent yields (Scheme 37). [104] Additionally, trifluroacetimidates as well as thio glycosyl donors underwent O-glycosylation in good yield under mild reaction conditions, afforded similar O-glycosides.…”

“…Later on, Mukherjee and co‐workers reported a novel route to synthesis the 2‐deoxy and 2,3‐unsaturated glycosides through a photo‐catalyzed system (Scheme 36). [103] The merger of tri‐ O ‐benzyl‐D‐glycal with TBHP in CH 3 CN and using eco‐friendly organic dye, eosin Y (1 mol%) under blue LED, afforded 2‐deoxy‐α‐alkoxy glycosides in decent yield. However, tri‐ O ‐acetyl‐D‐glycal and tri‐ O ‐benzoyl‐D‐glucal, leads to the synthesis of 2,3‐unsaturated glycosides in good yields.…”

Recent advances in photoinduced glycosylation: oligosaccharides, glycoconjugates and their synthetic applications

“…Synthesis of 2-iodo, 2-deoxy and 2,3-unsaturated glycosides were reported by Mukherjee and co-workers. 80 Reaction of peroxides with glycals, when carried out in the presence of NIS generates 2-deoxy-2-iodo-a-glycosides in good yields with predominant trans-diaxial selectivity at room temperature. Under photolytic conditions in the presence of a catalytic amount of eosin Y, 81 the reaction leads to 2-deoxyglycosides or 2,3-unsaturated-a-glycosides (Scheme 11).…”