Potential of neurotoxicity after a single oral dose of 4-bromo-, 4-chloro-, 4-fluoro- or 4-iodoaniline in rats

Selectivity Control on Hydrogenation of Substituted Nitroarenes through End-On Adsorption of Reactants in Zeolite-Encapsulated Platinum Nanoparticles

Platinum nanoparticles encapsulated into zeolite Y (Pt@Y catalyst) exhibit excellent catalytic selectivity in the hydrogenation of substituted nitroarenes to form the corresponding aromatic amines, even after complete conversion. With the hydrogenation of p-chloronitrobenzene as a model, the role of zeolite encapsulation toward perfect selectivity can be attributed to constraint of the substrate adsorbed on the platinum surface in an end-on conformation. This conformation results in the activation of only one adsorbed group, with little influence on the other one in the molecule. Owing to a much lower apparent activation energy of Pt@Y for the hydrogenation of a separately adsorbed nitro group than that of the adsorbed chloro group, the Pt@Y catalyst can prevent hydrodechlorination of p-chloronitrobenzene under mild conditions. Moreover, such a conformation results in a reduced adsorption energy of target p-chloroaniline on the platinum surface; thus suppressing the reactivity of hydrodechlorination of p-chloroaniline to circumvent further C-Cl bond breakage.

A recyclable nanoparticle-supported rhodium catalyst for hydrogenation reactions

Catalytic hydrogenation under mild conditions of olefins, unsaturated aldeydes and ketones, nitriles and nitroarenes was investigated, using a supported rhodium complex obtained by copolymerization of Rh(cod)(aaema) [cod: 1,5-cyclooctadiene, aaema^–: deprotonated form of 2-(acetoacetoxy)ethyl methacrylate] with acrylamides. In particular, the hydrogenation reaction of halonitroarenes was carried out under 20 bar hydrogen pressure with ethanol as solvent at room temperature, in order to minimize hydro-dehalogenation. The yields in haloanilines ranged from 85% (bromoaniline) to 98% (chloroaniline).

Biphenyl amide p38 kinase inhibitors 3: Improvement of cellular and in vivo activity

The biphenyl amides (BPAs) are a novel series of p38alpha MAP kinase inhibitor. The optimisation of the series to give compounds that are potent in an in vivo disease model is discussed. SAR is presented and rationalised with reference to the crystallographic binding mode.