Ein Molekül mit drei Gesichtern: Zwei der drei möglichen Konfigurationen eines stabilen Silicats mit fünf Kohlenstoffsubstituenten sowie ein dynamisches Gleichgewicht zwischen ihnen über eine Berry-Pseudorotation wurden NMR-spektroskopisch nachgewiesen. Die thermodynamischen und kinetischen Daten für diesen Prozess wurden durch Rechnungen bestätigt. In der Bildmitte ist die Hauptkonfiguration (aus der Kristallstrukturanalyse des nBu4N+-Salzes) wiedergegeben. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2004/z53006_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
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The synthesis and CysLT1 receptor affinities of a new series of highly rigid 3'- and 4'-(2-quinolinylmethoxy)- or 3'- and 4'-[2-(2-quinolinyl)ethenyl]-substituted, 6-, 7-, or 8-carboxylated flavones are described. CysLT1 receptor affinities of the flavones (down to 11 nM) were determined by their ability to displace [3H]LTD4 from its receptor in guinea pig lung membranes. Structure−affinity relationship studies showed that the relative positions of the carboxylic acid and the quinoline moiety were critical for CysLT1 affinities. While the carboxyl is optimal in the 8 position but tolerated in the 6 position, only the 6- and not the 8-tetrazole has significant activity. The quinoline moiety may be connected to the flavone skeleton by an ethenyl or a methoxy linker, but the substitution position is important for high affinity, especially in the 6-carboxylated flavones. 4'-Substituted 6-carboxyflavones are essentially inactive, whereas the 3'-substituted analogues have submicromolar CysLT1 affinity. Replacement of the quinoline by other heteroaromates generally leads to decreased affinities, with the phenyl and naphthyl analogues displaying only little or no affinity, while the 7-chloroquinoline analogue is comparable in activity to the quinoline. Flavones having CysLT1 receptor affinities of 10−30 nM were selected for determination of their inhibitory effects on the LTD4-induced contraction of guinea pig ileum in vitro. The IC50 values ranged between 15 and 100 nM. Compound 5d (8-carboxy-6-chloro-3'-(2-quinolinylmethoxy)flavone, VUF 5087) was selected for further research because of its high potency in the functional assay. This series contains the most rigid CysLT1 receptor antagonists known to date, and they are useful in the development of a CysLT1 antagonist model, which is discussed in the companion paper.
Das thermisch stabile Silylen Si{1,2-(NCH2tBu)2C6H4} reagiert mit 1H-Phosphirenen zu den ersten isolierten 2,3-Dihydro-1,3-phosphasileten, einem einzigartigen Typ von Zwitterion, und 1,2-Dihydro-1,2-phosphasileten. Das neuartige 2-Phospha-4-silabicyclo[1.1.0]butan (siehe Bild) ist eine reaktive Zwischenstufe der Reaktion, deren Verlauf durch die Wahl der Substituenten beeinflusst werden kann. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2004/z54183_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
18-Electron nucleophilic, Schrock-type phosphinidene complexes 3 [Cp*(Xy-N[triple bond]C)Ir=PAr] (Ar = Mes*, Dmp, Mes) are capable of unprecedented [1 + 2]-cycloadditions with 1 equiv of isocyanide RNC (R = Xy, Ph) to give novel iridaphosphirane complexes [Cp*(Xy-N[triple bond]C) IrPAr C=NR]. Their structures were ascertained by X-ray diffraction. Density functional theory investigations on model structures revealed that the iridaphosphirane complexes are formed from the addition of the isocyanide to 16-electron species [Cp*Ir=PAr] forming first complex 3 that subsequently reacts with another isocyanide to give the products following a different pathway than its nitrogen analogue [Cp*Ir[triple bond]Nt-Bu] 1.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Durch doppelte Addition des Phosphinidenkomplexes [PhPW(CO)5] an 2,5-Dimethyl-2,4-hexadien gelang erstmals die Synthese von Bisphosphiranen. Die s-trans-Konformation des Vinylphosphiran-Zwischenprodukts verhindert zwar eine Umlagerung und Epimerisierung, nicht aber die zweite Addition (siehe Schema).
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