Automated docking of 82 N-benzylpiperidine derivatives to mouse acetylcholinesterase and comparative molecular field analysis with 'natural' alignment

Automated docking and three-dimensional Quantitative Structure-Activity Relationship studies (3D QSAR) were performed for a series of 82 reversible, competitive and selective acetylcholinesterase (AChE) inhibitors. The suggested automated docking technique, making use of constraints taken from experimental crystallographic data, allowed to dock all the 82 substituted N-benzylpiperidines to the crystal structure of mouse AChE, because of short computational times. A 3D QSAR model was then established using the CoMFA method. In contrast to conventional CoMFA studies, the compounds were not fitted to a reference molecule but taken in their 'natural' alignment obtained by the docking study. The established and validated CoMFA model was then applied to another series of 29 N-benzylpiperidine derivatives whose AChE inhibitory activity data were measured under different experimental conditions. A good correlation between predicted and experimental activity data shows that the model can be extended to AChE inhibitory activity data measured on another acetylcholinesterase and/or at different incubation times and pH level.     

The Influence of Nanoscale Heterostructures on the Thermoelectric Properties of Bi‐substituted Tl5Te3

Tl_4.5Bi_0.5Te₃ crystallizes in a distorted variant of the Tl₅Te₃ structure type in the space group I4/m. The symmetry reduction compared to Tl₅Te₃ (space group I4/mcm) is a consequence of cation ordering as shown by resonant X‐ray scattering using synchrotron radiation. Tl and Bi predominantly occupy one Wyckoff site each. This ordering is accompanied by displacements of Te atoms. The influence of nanostructuring on the thermoelectric performance of Tl_4.5Bi_0.5Te₃ was investigated for the new composite model system Tl_4.5Bi_0.5Te₃ – TlInTe₂. For the nominal composition (Tl_4.5Bi_0.5Te₃)_0.6(TlInTe₂)_0.4, the thermoelectric Figure of merit ZT reaches 0.8 at 325 °C. Nanoscaled precipitates with sizes of about 100–200 nm probably have beneficial influence on the thermal conductivity at this temperature.     

Dienophilie des cyano-1 enamines,nouveaux equivalents de cetenes pour les cycloadditions de diels-alder1

The Diels-Alder reactivity of two captodative olefins, 2-morpho-lino-acrylonitrile $\text{15}$ and 2-(N-methlanilino) -acrylonitrile $\text{16}$, towards four conjugated dienes is evaluated.In every cases, isomeric {4+2} cyclo-adducts are obtained.With olefin $\text{15}$ yields are better than with olefin $\text{16}$. The adducts are easily transformed in to the corresponding ketones by a mild hydrolysis of the α-aminonitrile group. Thus, the 1-cyanoenamines can be considered as good ketene equivalents very useful for the synthesis of unsaturated cyclohexanones.     

Etude de la metallation de l'oxyde de diferrocenyl phenyl phosphine

The reaction of n-BuLi with phenyldiferrocenylphosphine oxide yields a mixture of two isomeric dianions. This mixture reacts with Me₃SiCl, Br₂, CO₂, PhCHO and PhCHNPh to give bifunctional products. With CoCl₂, Me₂SiCl₂, Ph₂SiCl₂, Bu₂SnCl₂ and PhCOOEt, the same mixture gives cyclic products. In almost every case each of these compounds is a mixture of two isomers corresponding to the original compound. The characteristic patterns of the PMR spectra are in full agreement with the structures proposed for the isomeric dianions.