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Archive for June 26, 2014

Hannover Medical School

A delegation of the Hannover Medical School (Medizinische Hochschule Hannover) has visited our Center today:

  • Dr. Tilman Fabian, Management Cluster of Excellence “Rebirth”, expert in management of interdisciplinary research projects
  • Prof. Dr. Ullrich Martin, Leibniz Research Laboratory for Biotechnology and Artificial Organs, expert in iPS cells
  • Prof. Dr. Denise Hilfiker-Kleiner, Dean of Research, Hannover Medical School, expert in experimental Cardiology
  • Dr. Robert Zweigerdt, Leibniz Research Laboratory for Biotechnology and Artificial Organs, expert in cell mass production/bioreactors
  • Dr. Andres Hilfiker, Leibniz Research Laboratory for Biotechnology and Artificial Organs, expert in Tissue Engineering
  • Prof. Dr. Axel Schambach, PhD, Department of Hematology, Hannover Medical School, expert in Experimental Hematology
  • Prof. Dr. Alexander Heisterkamp, Leibniz University Hannover, Hannover Laser Center, expert in Biophotonics

Excursion 23.06.2014

A group of bachelor students from the Faculty of Chemistry visited our Center today.

Chem. Commun. 2014

V.A. Rassadin, E. Nicolas, Y. Six

“Ti(OiPr)4/nBuLi: an attractive reagent system for [2+2+2] cyclotrimerisation reactions”

Chem. Commun. 2014, Advance Article

DOI: 10.1039/C4CC02698E

A convenient method for the [2+2+2] cyclotrimerisation of alkynes using Ti(OiPr)4/nBuLi is presented. Homotrimerisation of arylacetylenes proceeds within minutes with excellent regioselectivity. Moreover, the intermolecular construction of ABB heterotrimers can be achieved selectively from two different alkynes with similar electronic properties. The method is also suitable for the synthesis of pyridines.

Chem. Hetercycl. Compd. 2014

V.V. Sokolov, A.Yu. Ivanov, M.S. Avdontseva, A.A. Zolotarev

“Stereochemistry and NMR Spectra of Some Tricyclic Condensed Thiazolidine Derivatives with a Bridgehead Nitrogen Atom”

Chem. Hetercycl. Compd. 2014, 50, 550-556

DOI: 10.1007/s10593-014-1506-3

The configuration of a series of tricyclic condensed thiazolidines with a bridgehead nitrogen atom, for which erroneous data had been published, was determined by X-ray structural analysis and NMR spectroscopy.

G-RISC Workshop, part 2

The second part of the G-RISC workshop “NMR as interdisciplinary tool for the study of non-covalent interactions” took place on 16 and 18 June.
The program was as follows:

  • Regina Islamova “Transition Metal-Catalyzed polymerisation: NMR and EPR study”;
  • Roman Yakovenko “NMR study of protonation of carbonyl compounds (fluorinated enones and furanes) in Brønsted superacids”;
  • Konstantin Luzyanin “Combining NMR and MS tools for study of nano clusters in solution”;
  • Kirill Kulish “Zinc(II)-Mediated Generation of 5-amino-1,2,4-oxadiazoles from amidoximes and cyan amides”

Soon on TV

Shooting for a Saint-Petersburg TV channel.

Tetrahedron Lett. 2014

J. Malinina, T.Q. Tran, A.V. Stepakov, V.V. Gurzhiy, G.L. Starova, R.R. Kostikov, A.P. Molchanov

“[3+2] Cycloaddition reactions of arylallenes with C-(N-arylcarbamoyl)- and C,C-bis(methoxycarbonyl)nitrones and subsequent rearrangements”

Tetrahedron Lett. 2014, 55, 3663-3666

DOI: 10.1016/j.tetlet.2014.04.107

Print

The first example of 1,3-dipolar cycloaddition reactions of nitrones with arylallenes is described. C-Carbamoylnitrones react with the C1single bondC2 double bond of arylallenes affording the corresponding 4-methyleneisoxazolidines in good yields. N-Aryl-C,C-bis(methoxycarbonyl)nitrones usually gave rearranged products: mixtures of 4,5-dihydro-4-oxo-1H-benzo[b]azepine-2,2(3H)dicarboxylates and 4-oxo-1,5-diarylpyrrolidine-2,2-dicarboxylates.

Lecture 17.06.2014

RusChemSoc

St. Petersburg Branch of the Russian Chemical Society invites to a lecture of Prof. Dr. Hans-Heinrich Limbach from Dahlem Research School of Molecular Sciences of the Freie Universität Berlin, Germany

“Functional hydrogen bond NMR: from model systems to nano catalysts and enzymes”

The lecture will take place in Mendeleev’s center of the St. Petersburg State University (Universitetskaya nab. 7/9) on the 17 of June 2014 at 15:00. Additional info: 323-41-20.

Eur. J. Org. Chem. 2014

P. R. Golubev, A. S. Pankova, M. A. Kuznetsov

“Transition-Metal-Free Approach to 4-Ethynylpyrimidines via Alkenynones”

Eur. J. Org. Chem. 2014, 3614-3621

DOI: 10.1002/ejoc.201402045

A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4-yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines in yields of up to 85%.

Applied Magnetic Resonance 2014

M. Popova, D. Michel

“Behavior of Sodium Lauroyl Sarcosinate in Solution and Binary Mixtures by Means NMR”

Applied Magnetic Resonance 2014, 45, 353-364

DOI 10.1007/s00723-014-0531-9

Measurements of the 1H and 13C chemical shifts as well as 1H spin–lattice relaxation times of sodium lauroyl sarcosinate (SLAS) in aqueous solutions and mixed binary systems with co-surfactants were carried out at various concentrations. It will be shown that changes in the chemical shifts for the N–CH2 groups in SLAS with increasing surfactant concentration can be used to estimate the ratio pcis /ptrans of cis– and trans-isomers. The relative fraction p trans of molecules in trans-configurations increases the most in a narrow concentration range 0.007–0.034 mol/l, i.e., at the transition from the monomeric state to the micelle. The ratio pcis /ptrans asymptotically decreases with increasing concentration, reaching a constant value at concentrations significantly above the critical micelle concentration. Thus, the ratio can be related to the process of micellization. If micellization takes place, the cis-isomer starts to transform into trans-isomer because the trans-isomer is more favorable in micelles. Because of the smaller cross section of the polar group region, the trans-conformation can be more easily incorporated into the micelle. In summary, the occurrence of micellar aggregates at low SLAS concentration in mixed systems can be clearly inferred from the nuclear magnetic resonance spectra.