Cover Picture: A “Clickable” Hybrid Nanocluster of Cubic Symmetry (Chem. Eur. J. 19/2010)

Abstract

The absolute configuration of 1,2‐diols formed by a primary and a secondary (chiral) hydroxyl group can be deduced by comparison of the 1H NMR spectra of the corresponding (R)‐ and bis‐(S)‐MPA esters (MPA=methoxyphenylacetic acid). This method involves the use of the chemical shifts of substituents L1/L2 attached to the secondary (chiral) carbon, and of the hydrogen atom linked to the chiral center (CαH) as diagnostic signals. Theoretical (AM1, HF, and B3 LYP calculations) and experimental data (dynamic and low‐temperature NMR spectroscopy, studies on deuterated derivatives, constant coupling analysis, circular dichroism (CD) spectra, and NMR studies with a number of diols of known absolute configuration) prove that the signs of the ΔδRS obtained for those signals correlate with the absolute configuration of the diol. A graphical model for the reliable assignment of the absolute configuration of a 1,2‐diol by comparison of the NMR spectra of its bis‐(R)‐ and bis‐(S)‐MPA esters is presented.

Direct Enzymatic Branch‐End Extension of Glycocluster‐Presented Glycans: An Effective Strategy for Programming Glycan Bioactivity

“…By using this diversification tool, the conjugation of engineered sialic acid derivatives makes a straightforward extension possible, which can be used to determine its effect on lectin binding affinities with our test set of glycoclusters or other suitable scaffolds, for VAA or other biomedically relevant lectins . Remarkably, the method can be applied to spherical glyconanoclusters, facilitating work with vesicle‐presented glycodendrimers to yield programmable cell surfaces and natural or rationally engineered lectins…”

Recent advances in photoinduced glycosylation: oligosaccharides, glycoconjugates and their synthetic applications

“…The research on similar types of motifs was further extended by Fessner and coworkers who synthesized a hybrid nanocluster possessing cubic symmetry. 117 Chiara and coworkers discovered a versatile approach for the synthesis of highly functionalized cube-octameric polyhedral oligosilsesquioxane frameworks through click assembly. 118 A new type of glycocluster based on polyhedral oligosilsesquioxanes (POSS) was efficiently prepared by Lee in 2004 (Fig.…”

Acetylene Dicarboxylic Acid Diallyl Ester: A Versatile Monomer for Thiol–Ene Photocured Networks

“…The electron-deficient alkyne unit of ACDAE allowed us to apply these reactions without affecting the allyl groups. ACDAE was previously synthesized in literature as a precursor for the synthesis of various organic compounds, [40][41][42] hybrid nanoclusters, [43] and carbon nanotube functionalization. [44] To the best of our knowledge, within the photopolymerization studies, ACDAE was only used in one work where Song et al used it to prepare a triazole-based monomer for TEP.…”