Graft modification of crystalline nanocellulose by Cu(0)‐mediated SET living radical polymerization

Crystalline nanocellulose (CNC) was grafted with poly(methyl acrylate) (PMA) to yield modified CNC that is readily dispersed in a range of organic solvents [including tetrahydrofuran, chloroform, dimethylformamide, and dimethyl sulfoxide (DMSO)], in contrast to native CNC which is dispersible primarily in aqueous solutions. First, a CNC macroinitiator with high bromine initiator density was prepared through a 1,1′‐carbonyldiimidazole‐mediated esterification reaction in DMSO‐based dispersant. MA was then grafted from the CNC macroinitiator through SET living radical polymerization (LRP) at room temperature using Cu(0) (copper wire) as the catalyst. The LRP grafting proceeded rapidly, with ～30% monomer conversion achieved within 30 min, yielding approximately six times the mass of PMA with respect to CNC macroinitiator. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2800–2808     

Asymmetric Induction by Chiral Phosphorus

We report on the asymmetric induction by a chiral phosphorus atom contained in a 2-oxo-1,3,2-oxazaphosphorinane ring into an adjacent keto, alkane, or alkene function.     

Evaluation and optimization of solid adsorbents for the sampling of gaseous methylated mercury species

This study evaluates the suitability of commercially available adsorbents for the measurement of gaseous organic mercury species namely monomethylmercury (MMHg) and dimethylmercury (DMHg).     

Validation of a new HPLC‐UV method for determination of the antibiotic linezolid in human plasma and in bronchoalveolar lavage

A rapid and selective HPLC‐UV method was developed for the quantification of linezolid (LNZ) in human plasma and bronchoalveolar lavage (BAL) at the concentrations associated with therapy. Plasma samples were extracted by solid‐phase extraction followed by evaporation to dryness and reconstitution in mobile phase solution. The chromatographic separation was carried out on a C₁₈ column with an isocratic mobile phase consisting of dihydrogen phosphate buffer 50 mm (pH 3.5) and acetonitrile (60:40 v/v). The detection was performed using a photodiode array. Under these conditions, a single chromatographic run could be completed within 12 min. The method was validated by estimating the precision and the accuracy for inter‐ and intra‐day analysis in the concentration range of 25–25600 ng/mL. The method was linear over the investigated range with all the correlation coefficients R > 0.999. The intra‐ and inter‐day precision was within 8.90% and the accuracy ranged from ?4.76 to +5.20%. This rapid and sensitive method was fully validated and could be applied to pharmacokinetic study for the determination of LNZ levels in human plasma and BAL samples. Copyright © 2013 John Wiley & Sons, Ltd.     

Carbene‐Mediated Functionalization of the Anomeric C?H Bond of Carbohydrates: Scope and Limitations

Herein we investigate the scope and limitations of a new synthetic approach towards α‐ and β‐ketopyranosides relying on the functionalization of the anomeric C? H bond of carbohydrates by insertion of a metal carbene. A key bromoacetate grafted at the 2‐position is the cornerstone of a stereoselective glycosylation/diazotransfer/quaternarization sequence that makes possible the construction of a quaternary center with complete control of the stereochemistry. This sequence shows a good tolerance toward protecting groups commonly used in carbohydrate chemistry and gives rise to quaternary disaccharides with good efficiency. In the case of a disaccharide with a more restricted conformation, this functionalization process can be hampered by the steric demand next to the targeted anomeric position. In addition, the formation of transient orthoesters during the glycosylation step may also reduce the overall efficiency of the synthetic sequence.     

Identification of Dihydrocarveol Stereoisomers and Their Acetates Using Carbon-13 NMR Spectroscopy

The Carbon-13 NMR spectra of dihydrocarveol and dihydrocarvyl acetate stereoisomers are characterized. The chemical shifts are assigned taking account the steric and electronic substituent effects, the lanthanide induced shifts and the proton-carbon correlation.