Orthoamides and Iminium Salts LXXII: N,N,N′,N′,N′′,N′′,N′′′,N′′′‐Octamethyl‐(but‐2‐yne)‐bis(amidinium) Tetrafluoroborate: The First Bis‐amidinium Salt of Acetylenedicarboxyclic Acid. A New Superelectrophile?

A method for the preparation of the first acetylenedicarboxamidinium salt from a bis‐orthoamide derivative of acetylenedicarboxyclic acid has been established. The salt reacted with cyclopentadiene and furan at room temperature to give bicyclic [4+2]‐cycloaddition products. The solid compounds were characterized by solution NMR spectroscopy and by single‐crystal X‐ray diffraction. Quantum‐chemical calculations of the isolated N,N,N′,N′,N′′,N′′,N′′′,N′′′‐octamethyl‐acetylene‐bis(carboxamidinium) ion showed very good agreement with the spectroscopic and diffraction data.     

Orthoamides and iminium salts LXXII: N,N,N',N',N',N',N',N'-octamethyl-(but-2-yne)-bis(amidinium) tetrafluoroborate: the first bis-amidinium salt of acetylenedicarboxyclic acid. A new superelectrophile?

A method for the preparation of the first acetylenedicarboxamidinium salt from a bis-orthoamide derivative of acetylenedicarboxyclic acid has been established. The salt reacted with cyclopentadiene and furan at room temperature to give bicyclic [4+2]-cycloaddition products. The solid compounds were characterized by solution NMR spectroscopy and by single-crystal X-ray diffraction. Quantum-chemical calculations of the isolated N,N,N',N',N',N',N',N'-octamethyl-acetylene-bis(carboxamidinium) ion showed very good agreement with the spectroscopic and diffraction data.     

Kokain

Cocaine was isolated from dried tea leaves and chromatographically purified by HPLC. The UV‐, CD‐, IR‐ NMR‐ und MS‐spectra are reproduced in the supplementary material. The NMR‐ and mass‐spectra have been interpreted and compared with theoretical calculations of the ¹³C chemical shifts. The project is a follow up of the recent book “Classics in Spectroscopy” by S. Berger und D. Sicker (Wiley‐VCH 2009).     

Ein Wirkstoff gegen Malaria aus der Natur: Artemisinin

Artemisinin, an unusual tetracyclic, endoperoxidic sesquiterpene is a highly bioactive natural product. Due to its superior activity against the malaria parasite it is under investigation to an extraordinary extent. The Chinese scientist Tu Youyou who discovered the compound received the Nobel Prize for medicine 2015. However, treating malaria is not all of its potential. This paper is following up two recent articles on artemisinin in this Journal from 2014. We describe here the isolation of pure crystalline artemisinin from dried sweet wormwood leaves and present its complete set of spectra together with interpretations. Background information complements the matter.     

Gaussian 03 Workshop

Das Programmpaket „Gaussian”︁, eines der größten und am häufigsten genutzten quantenchemischen Rechenprogramme, ist Ende März in der neuen Version „Gaussian 03”︁ erschienen. Der weltweit erste Workshop zu diesem Programmpaket, „Introduction to Gaussian 03, Theory and Practice”︁, hat Anfang April an der Universität Ulm stattgefunden. Vorbereitet und organisiert wurde der Workshop in Ulm von Hans‐Ullrich Siehl, Abteilung Organische Chemie I und dem Center of Exellence (CoE) for Computational Chemistry der Universität Ulm ‐ eine Einrichtung des Kommunikations‐und Informationszentrums (KIZ) der Universität Ulm (Leiter: Hans Peter Großmann) ‐ in Zusammenarbeit mit Sun Microsystems und Gaussian.