Der Widerspenstigen Zähmung: Ein Rutheniumdiphosphan‐Katalysator ermöglichte eine beispiellose Selektivität von über 94 % bei gutem Umsatz (20 %+) in der Ethanolveredelung zu 1‐Butanol (siehe Bild; P orange, Ru blau). Mechanistische Studien zeigen, dass die Acetaldehyd‐Aldolkondensation vermutlich am Metall stattfindet und ihre gezielte Kontrolle entscheidend für die hohe Selektivität ist.
A new method to aid the determination of structures of sterically crowded molecules in the gas phase by dynamically linking the gas-phase electron diffraction (GED) refinement process with computational methods has been developed. The procedure involves refining the heavy-atom skeleton of the molecule using the GED data while continually updating the light-atom positions during the refinement using computational methods, in this case molecular mechanics. This removes errors associated with the assumption of local symmetry for the light-atom groups, which can affect the final values of the heavy-atom parameters. The refinement of the molecular structure of tri-tert-butyl phosphine oxide has been used to illustrate this new technique, which we call the DYNAMITE (DYNAMic Interaction of Theory and Experiment) method. Re-examination of the structure using this method has resulted in a shorter P-O distance than was found in a less sophisticated anaylsis, and is consistent with the molecule being regarded as O=PBut3, rather than O(-)-P+But3.
Eine einfache Pd‐katalysierte ortho‐selektive Bromierung und Chlorierung von Aniliden gelingt unter aeroben Bedingungen bei Raumtemperatur, wenn N‐Halogensuccinimide (NXS) in Gegenwart von p‐Toluolsulfonsäure (PTSA) eingesetzt werden. Der orthopalladierte PTSA‐Komplex ist nicht nur katalytisch aktiv, sondern geht auch einen reduktiven Prozess unter Bildung eines ungewöhnlichen PdI‐PdII‐Tetramers ein (siehe Struktur; Pd grün, O rot, S gelb, C grau).
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