Up to 96% Enantioselectivities in the Hydrogenation of Fluorine Substituted (E)-2,3-Diphenylpropenoic Acids over Cinchonidine-Modified Palladium Catalyst
High enantioselectivities, up to 96%, were obtained in the hydrogenation of some disubstituted derivatives, unprecedented in the hydrogenation of prochiral unsaturated carboxylicacidsovermodified heterogeneous catalyst. The best optical purities were reached in the hydrogenation of derivates bearing a para-substituent on the β phenyl and an ortho-substituent on the α phenyl ring, respectively. The
CH…F hydrogen bonds as the organising force in F-substituted α-phenyl cinnamic acid aggregates studied by the combination of FTIR spectroscopy and computations
作者:B. Tolnai、J.T. Kiss、K. Felföldi、I. Pálinkó
DOI:10.1016/j.molstruc.2008.10.030
日期:2009.4
Various F-substituted E-2,3-diphenyl propenoic acid molecules were synthesised and their aggregation behaviour was studied by experimental (FT-IR spectroscopy) and computational (semiempirical and DFT) methods. Experimental approach embraced the identification of potential hydrogen bonding sites through finding the relevant IR bands and monitoring their shifts upon increasing the acid concentration and on going to the solid state. It Was found that fluorine engaged in C-H center dot center dot center dot F hydrogen bonding easily, where the carbon atom could be of any kind available in the molecule (aromatic, aliphatic or olefinic). Shifts were found even in moderately concentrated solutions and in the solid state too. Hydrogen bonding sites could be assigned and relevant aggregate models could be built. Molecular modelling allowed obtaining good estimates for hydrogen bond lengths and angles and visualisation of the geometric arrangements even of extended networks also became feasible. (C) 2008 Elsevier B.V. All rights reserved.
Design, synthesis, and biological evaluation of compounds with a new scaffold as anti-neuroinflammatory agents for the treatment of Alzheimer's disease
These compounds were validated for their anti-neuroinflammatory activity in BV2 cells. Experimental results reveal that the most active compound 8b can inhibit nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) production with IC50 values of 1.0, 2.6, and 0.5 μM, respectively. The compound can also significantly modulate the MAPK pathways through inhibiting the phosphorylation