2-Deoxy-2-iodo-β-glucopyranosyl Fluorides:  Mild and Highly Stereoselective Glycosyl Donors for the Synthesis of 2-Deoxy-β-glycosides from β-Hydroxy Ketones

Abstract

2-Deoxy-2-iodo-beta-glucopyranosyl fluoride 14 is a highly stereoselective glucopyranosyl donor that may be activated under mild conditions. Application of this new glycosyl donor to the glycosidation reactions of a variety of acceptors including beta-hydroxy ketones affords beta-glycosides with high efficiency and stereoselectivity. [reaction--see text]

Methods for 2-Deoxyglycoside Synthesis

“…For example, Blanchard and Roush 309 described the application of 2-deoxy-2-iodo-β-glucopyranosyl fluoride 253 , which contains a C6-bromo substituent. The halo-containing glycosyl donor could be activated under mild conditions.…”

Stereoselective Synthesis of α‐Linked 2‐Deoxy Glycosides Enabled by Visible‐Light‐Mediated Reductive Deiodination

“…further demonstrated that the iodo‐substituent at the C‐2 position well controlled the stereochemistry of the newly formed glycosidic bond 11. This character was further illustrated in the glycosylation of 2‐deoxy‐2‐halo‐glycosyl trifluoroacetimidtaes,8a trichloroacetimidates,12a–c thioethers,12d,e and fluorides,12f,g which provided the corresponding 2‐deoxy‐2‐halo‐glycosides, and after reductive removal, the 2‐deoxy‐glycosides with high stereroselectivity. Meanwhile, the use of oxidative coupling of glycals in the preferential synthesis of 2‐deoxy‐2‐halo‐α‐glycosides was developed by Lemieux,13a Tatsuta,13b Thiem,13c,d Kessler,13e and Danishefsky,13f respectively.…”

Additive‐Free Gold(III)‐Catalyzed Stereoselective Synthesis of 2‐Deoxyglycosides Using Phenylpropiolate Glycosides as Donors

“…[4] The lack of stereo-directing group at C2 position makesi tm ore arduous task to control the desired stereochemical outcome at the anomeric center.N evertheless, there are severalw ell documenteds ynthetic methods availablei nt he literature for making 2-deoxyglycosides. First, indirect approach-where temporary participating/non-participating functionality such as -Br, [6] -I, [7] -SR, [8] -SePh, [9] -OAc [10] is introduced at C2-position to control the stereochemical outcomea tt he anomeric position. Literature survey disclosed two approaches have mainly been adopted for stereochemical syntheses of 2-deoxyglycosides.…”

“…Literature survey disclosed two approaches have mainly been adopted for stereochemical syntheses of 2‐deoxyglycosides. First, indirect approach‐ where temporary participating/non‐participating functionality such as ‐Br, ‐I, ‐SR, ‐SePh, ‐OAc is introduced at C2‐position to control the stereochemical outcome at the anomeric position. The major roadblocks of these approaches are the requirements of additional synthetic steps: installation followed uninstallation of the temporary group after the desired operation, which eventually decreases the overall efficacy of the reactions.…”