Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• [44]. Compound 5: A stirred solution of glycosyl thiol 1b (49.8 mg, 0.21 mmol, 3 equiv), 2b (13.7 mg, 0.07 mmol, 1 equiv) and DPAP (5.1 mg, 0.02 mmol, 0.3 equiv) in DMF (660 μL) was irradiated at room temperature for 30 min and then concentrated. The residue was purified by silica flash chromatography

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• applications and we highlight these examples below. In 2016, the Rademann group could obtain 2-deoxy-2-N-acetyl glycosyl thiols using DMC, NEt3, and either BzSH or AcSH (Scheme 25) [80]. The authors noticed that the reaction proceeds through the detected oxazoline intermediate to provide solely the β-glycosyl

• thiol in moderate to excellent yield. They proposed that the oxazoline intermediate blocks access to the α-face of the molecule, hence accounting for the excellent stereoselectivity of the reaction. They then demonstrated the power of this method as a ligation strategy. The protected thiol can be

DNA display of glycoconjugates to emulate oligomeric interactions of glycans

• Alexandre Novoa and
• Nicolas Winssinger

Beilstein J. Org. Chem. 2015, 11, 707–719, doi:10.3762/bjoc.11.81

• ]. The first method reported was leveraged on a nucleophilic coupling between readily available glycosyl thiol (obtained in one step by treatment of a native carbohydrate with Lawesson’s reagent [37]) and a chloroacetamide-functionalized PNA (Scheme 7) [38][39]. Using this method, we have shown that

Orthogonal dual thiol–chloroacetyl and thiol–ene couplings for the sequential one-pot assembly of heteroglycoclusters

• Michele Fiore,
• Gour Chand Daskhan,
• Baptiste Thomas and
• Olivier Renaudet

Beilstein J. Org. Chem. 2014, 10, 1557–1563, doi:10.3762/bjoc.10.160

• reactions give clean reaction mixtures to provide the hGC 11 with 77% yield. The same strategy was followed to prepare compound 13 featuring two α-D-Man and four β-D-GlcNAc. No difference of reactivity was observed whatever the scaffold or the glycosyl thiol used. All these products were obtained in good

Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

• Tamashree Ghosh,
• Abhishek Santra and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 974–982, doi:10.3762/bjoc.9.112

• thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium

• carbonotrithioate. The reaction conditions are reasonably simple and yields were very good. Keywords: Appel reagent; carbon tetrabromide; glycosyl hemiacetal; glycosyl thiol; thioglycoside; triphenylphosphine; Introduction Thioglycosides (1-thiosugar) are widely used glycosyl donors in glycosylation reactions [1

• , instability of the starting materials (glycosyl bromides, etc.), multiple steps, unsatisfactory yields, use of metallic salts, use of expensive reagents, pregeneration of glycosyl isothiouronium salts, etc. Similar to thioglycosides, glycosyl thiol derivatives are useful intermediates for the synthesis of