Issue 11, 2025

Investigating the stereo-directing effect of remote participating groups on selectivity in the 2-deoxyglycosylation of galactal

Abstract

Chemical glycosylation is arguably crucial for assembling the structurally defined polysaccharides and glycoconjugates of distinctive biological functions. Predicting and governing the stereochemical outcome in the glycosylation reaction is undoubtedly more challenging and influenced mainly by the configuration of protecting groups (PGs) and ring conformers. In this paper, we exploited the direct influence of stereoelectronically diverse PGs on the anomeric selectivity in 2-deoxyglycosylation. The galactal donors with C-4 O-pivaloyl as a higher electron density group ensured enhanced α-selectivity; practically, trichloroacetimidate (O-TCA) ensured optimal selectivity, affirming the covalent remote group participation (RGP) featuring distinctive ring-bridging oxazepine structures. Mechanistic investigations employing density functional theory (DFT) and experimental studies revealed the perspective of RGP by distal C-4 PGs, which facilitate the stabilization of 4H3 and 3H4 conformations of oxocarbenium ions via dioxolenium species.

Graphical abstract: Investigating the stereo-directing effect of remote participating groups on selectivity in the 2-deoxyglycosylation of galactal

Supplementary files

Article information

Article type
Research Article
Submitted
14 Dec 2024
Accepted
06 Mar 2025
First published
06 Mar 2025

Org. Chem. Front., 2025,12, 3426-3437

Investigating the stereo-directing effect of remote participating groups on selectivity in the 2-deoxyglycosylation of galactal

N. Kumar, A. Yadav and S. Kashyap, Org. Chem. Front., 2025, 12, 3426 DOI: 10.1039/D4QO02329C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements