Hydroxoiridium/Chiral Diene Complexes as Effective Catalysts for Asymmetric Annulation of α‐Oxo‐ and Iminocarboxamides with 1,3‐Dienes

The asymmetric [3+2] annulation of α‐oxo‐ and α‐iminocarboxamides with 1,3‐dienes catalyzed by hydroxoiridium/chiral diene complexes was realized, giving high yields of the corresponding γ‐lactams with high enantioselectivity.     

"Click-made" biaryl-linker improving efficiency in protein labelling for the membrane target protein of a bioactive compound

We report on the design, synthesis and assessment of a novel biaryl-linked (BArL) molecular probe for the exploration of low-abundant target proteins for bioactive compounds based on the activity based protein profiling (ABPP) approach. Surprisingly, the performance of the BArL probe was better than that of the stepwise tagging approach that is considered to be the most effective method used in ABPP study.     

High-performance gel filtration of water-soluble samples on polyvinyl alcohol columns

The chromatographic behaviour in aqueous solution of pullulans, polyethylene glycols, peptides and proteins with different molecular weights on newly developed polyvinyl alcohol columns (Asahipak GS column series: GS-310, GS-320, GS-510 and GS-520) has been investigated. Pullulans and polyethylene glycols eluted according to the gel filtration mode, so both series of compounds produced almost equal calibration curves for GS-310 and GS-320 and for GS-510 and GS-520; the exclusion limits on GS-310 and GS-320 and on GS-510 and GS-520 were found to be ca. 40,000 and 300,000, respectively. Peptides and proteins were found to adsorb slightly on the columns. However, the plots of the elution volumes against the logarithm of the molecular weights for many of the substrates tested gave rise to the linear calibration curves. Recovery of several crude proteins was also studied for the columns and high values were obtained (81–100%). The effects of changes in the flow-rate, temperature and concentration of electrolytes added to the eluents, on the retention of all four types of compound are also reported.     

Theoretical calculations of magnetic moments of mono-cyclic conjugated hydrocarbons

The magnetic moments of excited states of mono-cyclic non-alternant conjugated hydrocarbons with 3-9 carbon atoms were theoretically calculated using wavefunctions determined on the basis of the LCAO MO method. The predicted value is in good agreement with experiment for the tropylium cation.     

Untersuchungen über Hydratation von Metallhalidrauchen mit Elektronenbeugung

Zusammenfassung Mittels Elektronenbeugung wurden Versuche durchgeführt, die Hydratationsf?higkeit einiger Metallhalide festzustellen. Bei den Cd-Haliden nimmt die Hydratationsf?higkeit nach folgender Reihe ab: CdCl₂>CdBr₂>CdJ₂ und bei Metallchloriden nach folgender Reihe ZnCl₂>CdCl₂>PbCl₂>HgCl₂>Hg₂Cl₂ ab. Diese Ergebnisse entsprechen dem Anionen- oder Kationendurchmesser. Für 80% rel. Feuchtigkeit zeigen Hg₂Cl₂ und PbCl₂ Platzwechsel der Atome.