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

• binary combinations of α-D-Man or β-D-GlcNAc, thus providing rapid access to attractive heteroglycosylated platforms for diverse biological applications. Keywords: chemoselective ligation; heteroglycocluster; multivalency; multivalent glycosystems; one-pot synthesis; Introduction Multivalent

• was irradiated at 365 nm for 45 min. Compound 4 (6.9 mg, 46%) was obtained as a white foam. Analytical RP-HPLC: tR = 9.71 min (gradient: 5 to 100% B in 20 min); ESIMS+ (m/z): [M + H]+calcd for C94Cl2H158N16O40S4, 2351.9; found, 2352.0. Heteroglycocluster 5. Route A: Compounds 4 (6.9 mg, 0.029 mmol

• % B in 20 min); ESIMS+ (m/z): [M + H]+ calcd for C110H187N18O60S6, 2753.1; found, 2753.2. Heteroglycocluster 5. Route B (one-pot assembly). Compounds 2 (3.6 mg, 0.015 mmol) and 3 (10 mg, 0.0064 mmol) were dissolved in dry DMF (300 µL) and NaH (0.5 mg, 0.015 mmol) was added. After stirring 1 h at room

Synthesis of heteroglycoclusters by using orthogonal chemoselective ligations

• Baptiste Thomas,
• Michele Fiore,
• Isabelle Bossu,
• Pascal Dumy and
• Olivier Renaudet

Beilstein J. Org. Chem. 2012, 8, 421–427, doi:10.3762/bjoc.8.47

• : chemoselective ligation; click chemistry; cyclopeptide; heteroglycocluster; oxime; Introduction Multivalent interactions between carbohydrates and proteins play key roles in diverse biological events, including fertilization, cell–cell communication, host–pathogen interactions, immune response and cancer

• different sugar units instead of a single motif, namely heteroglycocluster, reflects the presence of sugars found in native biological systems more closely than homoglycocluster does. Although recognition mechanisms are not fully understood, these studies suggest that heteroglycoclusters should interact

• heteroglycoclusters by using a protocol based on orthogonal chemoselective ligations. Two series of compounds containing different combinations of two different sugars have been designed (Figure 1). In one series (heteroglycocluster 2:2), two αMan, αFuc and/or βLac are conjugated at alternate positions into the