Synthesis of a 2-N,N-dibenzylamino glucopyranosyl trichloroacetimidate glycosyl donor and evaluation of its utility in stereoselective glycosylation

Stacy P Ali; Nigel Kevin Jalsa

doi:10.1016/j.carres.2015.11.007

Synthesis of a 2-N,N-dibenzylamino glucopyranosyl trichloroacetimidate glycosyl donor and evaluation of its utility in stereoselective glycosylation

Carbohydr Res. 2016 Feb:420:13-22. doi: 10.1016/j.carres.2015.11.007. Epub 2015 Dec 9.

Authors

Stacy P Ali¹, Nigel Kevin Jalsa²

Affiliations

¹ Department of Chemistry, The University of the West Indies, St. Augustine, Trinidad and Tobago.
² Department of Chemistry, The University of the West Indies, St. Augustine, Trinidad and Tobago. Electronic address: nigel.jalsa@sta.uwi.edu.

PMID: 26717545
DOI: 10.1016/j.carres.2015.11.007

Abstract

The 2-N,N-dibenzylamino glucopyranosyl trichloroacetimidate donor was synthesized and an extensive investigation of its glycosyl donor properties was conducted. Coupling studies incorporated a variety of glycosyl promoters and a range of acceptor alcohols representing different reactivities and protecting group patterns. Various reaction temperatures, solvents and glycosylation protocols were also examined. Exclusive β-stereoselectivity was obtained in moderate to good yields with eight novel glycosides being produced, by probable neighbouring group participation via the formation of an aziridinium ion intermediate. Plausible reaction mechanisms were proposed based on the results obtained.

Keywords: 2-N,N-Dibenzylamino; Aziridinium ion; Glycosyl trichloroacetimidate; Glycosylation; β-Stereoselectivity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acetamides / chemistry*
Chloroacetates / chemistry*
Glycosides / chemical synthesis*
Glycosides / chemistry
Glycosylation
Molecular Structure
Stereoisomerism
Temperature

Substances

Acetamides
Chloroacetates
Glycosides
trichloroacetamide