Zwei unerwartete Umformungen: Bei der Reaktion des Huisgen‐Zwitterions, das sich von Triphenylphosphan und Diisopropylazodicarboxylat (DIAD) ableitet, mit Chalkonen entstehen funktionalisierte Pyrazoline, während die Reaktion mit Dienonen Pyrazolopyridazine liefert, vermutlich über eine Diels‐Alder‐Reaktion des zunächst gebildeten Pyrazolins mit im Überschuss vorliegendem DIAD (siehe Schema).
Ungerade Wassercluster: Ein bislang unbekanntes propellerförmiges Wasserundecamer wird im Gitter des Heptahydrochlorids eines C3‐symmetrischen homoditopen Octaaminocryptanden stabilisiert. Die diskreten Wassercluster ordnen sich symmetrisch um die Cryptanden an und wechselwirken mit darin eingeschlossenen Chloridionen (siehe Struktur; Cl grün, O rot, N blau).
A monoprotected amino acid Bz-Gly-OH assists in the allylic alkylation of a variety of ketones, β-keto esters, aldehydes, etc., during enamine− palladium catalysis. Density functional theory calculations reveal that Bz-Gly-OH assists in the formation of an enamine that attacks the π-allylpalladium complex via an outer sphere mechanism. The preliminary result points to an asymmetric allylic alkylation under a new mode of bifunctional catalysis.
Coordinatively unsaturated double‐stranded helicates [(H2L)2Eu2(NO3)2(H2O)4](NO3)4, [(H2L)2Tb2(H2O)6](NO3)6, and [(H2L)2Tb2(H2O)6]Cl6 (H2L=butanedioicacid‐1,4‐bis[2‐(2‐pyridinylmethylene)hydrazide]) are easily obtained by self‐assembly from the ligand and the corresponding lanthanide(III) salts. The complexes are characterized by X‐ray crystallography showing the helical arrangement of the ligands. Co‐ligands at the metal ions can be easily substituted by appropriate anions. A specific luminescence response of AMP in presence of ADP, ATP, and other anions is observed. Specificity is assigned to the perfect size match of AMP to bridge the two metal centers and to replace quenching co‐ligands in the coordination sphere.
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