Platinum(II) terpyridine complexes with glycosylated acetylide and arylacetylide ligands bind to DNA with binding constants approximately 10(5) mol(-1) dm(3); the glycosylated arylacetylide complexes exhibit emission at lambda(max) approximately 620 nm in water and are up to approximately 100-times higher in potency than the clinical cisplatin drug in killing cancer cells.

Persuaded with gold: The title reaction in the presence of [Ph3PAuNTf2] (Tf=trifluoromethanesulfonyl) led conveniently to the corresponding nucleosides with excellent regioselectivity (see scheme). Even purine derivatives underwent this transformation owing to the mild conditions, which enabled the use of protecting groups that would not usually be compatible with N‐glycosylation conditions.

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Stereoselective synthesis of N-alkyl-D-allosamines, designed for the preparation of N-alkyl derivatives of allosamidin (a chitinase inhibitor), is achieved by a 'carbonyl group transfer' reaction followed by stereoselective reduction and this method represents the first example of N-alkyl-D-allosamines synthesized from a 2-oxosugar.

Überredet mit Gold: Die Titelreaktion liefert in Gegenwart von [Ph3PAuNTf2] (Tf=Trifluormethansulfonyl) bequem und hoch regioselektiv die jeweiligen Nucleoside (siehe Schema). Sogar Purinderivate können umgesetzt werden, weil die milden Bedingungen den Einsatz von Schutzgruppen ermöglichen, die mit den gängigen N‐Glycosylierungsbedingungen inkompatibel sind.

Chitosan (1) was prepared by basic hydrolysis of chitin of an average molecular weight of 70000 Da, 1 H-NMR spectra indicating almost complete deacetylation. N-Phthaloylation of 1 yielded the known Nphthaloylchitosan (2), which was tritylated to provide 3a and methoxytritylated to 3b. Dephthaloylation of 3a with NH 2 NH 2 · H 2 O gave the 6-O-tritylated chitosan 4a. Similarly, 3b gave the 6-O-methoxytritylated 4b. CuSO 4 -Catalyzed diazo transfer to 4a yielded 95% of the azide 5a, and uncatalyzed diazo transfer to 4b gave 82% of azide 5b. Further treatment of 5a with CuSO 4 produced 2-azido-2-deoxycellulose (7). Demethoxytritylation of 5b in HCOOH gave 2-azido-2-deoxy-3,6-di-O-formylcellulose (6), which was deformylated to 7. The 1,3-dipolar cycloaddition of 7 to a range of phenyl-, (phenyl)alkyl-, and alkylmonosubstituted alkynes in DMSO in the presence of CuI gave the 1,2,3-triazoles 8 -15 in high yields. 2-Azido-2-deoxycellulose should be available from chitosan by diazo transfer. 1,3-Cycloadditions of 2-azido-2-deoxycellulose to alkynes should introduce 1,2,3-triazolyl side chains into chitosan and formally into cellulose, similarly as it is known for 6-azido-6-deoxypolysaccharides [20] [21] 1 ). In the following, we describe the synthesis of 2-azido-2-deoxycellulose and its reactivity in the 1,3-dipolar cycloaddition to alkynes, leading to new chitin/cellulose derivatives.

Poly- l -lactic acid (PLLA) is a prospective renewable and degradable material, but slow crystallization limits its processing and application. By dehydration condensation of hydroxyl-terminated hyperbranched resin (H202) and carboxylated carbon nanotubes (CNTs), a modified CNT, CNTs-H202, was obtained. Grafting was confirmed by Fourier transform infrared (FTIR) spectroscopy, and the grafting content was assessed by thermogravimetric analysis (TGA). Changes in surface atom content were explored by X-ray electron spectroscopy (XPS). Transmission electron microscopy (TEM) observed the increase of black dots on the surface of carbon nanotubes. PLLA/CNTs and PLLA/CNTs-H202 composites were prepared, and differential scanning calorimetry (DSC) was used to investigate the crystallization behavior of the composites. The results showed that during the cooling process, PLLA/CNTs-H202 had a larger crystalline full width at half-maximum (FWHM) compared with PLLA/CNTs and exhibited the ability to hinder chain segment movement during the subsequent reheating process. The crystallization activation energy was calculated by the Kissinger method, and it was found that the activation energy of the carbon tube increased slightly after grafting. Wide-angle X-ray diffraction (WAXD) once again proved the improvement of the crystallization ability. The results of polarized optical microscopy (PLOM) showed that the number of crystal nuclei increased and the crystal became smaller.

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