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Jörg Stierstorfer Dr. Karina R. Tarantik Dipl.‐Chem. Thomas M. Klapötke Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(23):5775-5792
A new way to make a bang : Several functionalized 1‐ethyl‐5‐aminotetrazoles, 1‐ethyl‐5‐nitrimino‐tetrazoles, and copper complexes have been synthesized and their chemical and energetic properties have been comprehensively characterized. The compounds belong to all classes of “energetic materials”: explosives, propellants, and pyrotechnics.
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Electron disco: A “quantum stroboscope” for capturing the electron motion on a subfemtosecond timescale for a particular class of problems is highlighted. The picture shows a diffraction pattern caused by wave packets obtained by synchronizing attosecond UV pulses to a near‐IR field and ionizing rare‐gas atoms.
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Vaibhav M. Jadhav Vinod Scaria Dr. Souvik Maiti Dr. 《Angewandte Chemie (International ed. in English)》2009,48(14):2557-2560
Many important cellular processes are regulated by small endogenous noncoding RNAs known as microRNAs (miRNAs). The precise molecular function of many miRNAs is unknown; different loss‐of‐function methods are required to gain insight into the biology of these small RNA molecules. Nucleic acid enzymes termed antagomirzymes are now shown to be valuable tools for the specific knockdown of miRNA in vitro and in vivo (see scheme).
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Christophe Aronica Dr. Anna Venancio‐Marques Jérôme Chauvin Dr. Vincent Robert Dr. Gilles Lemercier Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(20):5047-5055
Finely tuned optical properties : The optical properties of substituted protected catechol derivatives can be fine‐tuned (see scheme; TBDMS=tert‐butyldimethylsilyloxy). The DFT‐calculated polarisabilities are compared with experimental data.
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Tilman Lechel Dieter Lentz Prof. Dr. Hans‐Ulrich Reissig Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(22):5432-5435
By a flexible three‐component synthesis, alkoxy‐substituted enamides are easily available from lithiated alkoxyallenes, nitriles and carboxylic acids (see scheme). The treatment of these versatile intermediates with trifluoroacetic acid provided 5‐acetyloxazoles in moderate to good yields. Different substituents are possible at C‐2 and C‐5 and the 5‐acetyl group is a suitable handle for further synthetic transformations.
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Jens Kurreck Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(8):1378-1398
An efficient mechanism for the sequence‐specific inhibition of gene expression is RNA interference. In this process, double‐stranded RNA molecules induce cleavage of a selected target RNA (see picture). This technique has in recent years developed into a standard method of molecular biology. Successful applications in animal models have already led to the initiation of RNAi‐based clinical trials as a new therapeutic option.
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Christian Wasmer Laura Benkemoun Dr. Raimon Sabaté Dr. Michel O. Steinmetz Dr. Bénédicte Coulary‐Salin Dr. Lei Wang Dr. Roland Riek Prof. Sven J. Saupe Dr. Beat H. Meier Prof. 《Angewandte Chemie (International ed. in English)》2009,48(26):4858-4860
Protein deposition frequently occurs as inclusion bodies (IBs) during heterologous protein expression in E. coli. The structure of these E. coli IBs of the prion‐forming domain from the fungal prion HET‐s is the same as that previously determined for fibrils assembled in vitro, and show prion infectivity. These results demonstrate that the IBs of HET‐s(218–289) are amyloids.
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Grégory Schmidt Salomé Gallon Stéphane Esnouf Dr. Jean‐Philippe Bourgoin Dr. Pascale Chenevier Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(9):2101-2110
On the tube : The coupling of diazonium ions onto single‐walled carbon nanotubes is shown to proceed through a radical chain reaction by kinetic analysis of the absorption peak drop (see picture). Radical species are also revealed by ESR. Metallic (m) nanotubes play a special catalytic role in the functionalization of semiconducting (sc) nanotubes.
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Juan Tolosa Dr. Chris Kub Uwe H. F. Bunz Prof. 《Angewandte Chemie (International ed. in English)》2009,48(25):4610-4612
Out on a limb : Sonogashira coupling of a suitable AB2 monomer containing two iodine and one alkyne group forms a hyperbranched conjugated polymer that is studded with iodine end groups (see picture: I purple). These iodine groups are a perfect handle for convenient, efficient, and high‐yielding post‐functionalization to access hyperbranched, fluorescent poly(phenyleneethynylene)s.
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Hao Sun Fang‐Zheng Su Ji Ni Yong Cao Prof. He‐Yong He Prof. Kang‐Nian Fan Prof. 《Angewandte Chemie (International ed. in English)》2009,48(24):4390-4393
Two birds with one auric stone : The title system acts as a highly efficient heterogeneous catalyst for the one‐pot tandem synthesis of imines or oximes from alcohols and the corresponding amines under mild conditions (see scheme; HAP= hydroxyapatite).
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Julia Schöffel Andrey Yu. Rogachev Dr. Serena DeBeer George Dr. Peter Burger Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4734-4738
An N for Ir : The synthesis and X‐ray crystal structure of a late‐transition‐metal complex with a terminal nitrido ligand and its hydrogenation to the related amido complex are reported (see scheme).
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Manuela Gaab Stéphane Bellemin‐Laponnaz Dr. Lutz H. Gade Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(22):5450-5462
Trapped in a “tea bag” : Membrane bags, fabricated from a dialysis membrane, have been employed as semipermeable containers for dendrimer‐immobilised oxazoline–copper(II) Lewis acid catalysts. Dipping them into reactant solutions leads to the catalytic conversion of the substrates, which penetrate the membrane as does the product in the reverse direction (see scheme).
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Simon Reitz Menekse Cebi Philipp Reiß Gregor Studnik Uwe Linne Ulrich Koert Prof. Dr. Lars‐Oliver Essen Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4853-4857
The attachment of modulators to a trimeric porin ion channel was investigated (see picture of the trimer with a crown ether modulator (orange)). The interplay of modulator and protein is essential for the conformational heterogeneity of the hybrid channel. Single‐site attachment in large pores is not sufficient to change the electrophysiological characteristics of the pores—such change requires additional noncovalent interactions or second‐site attachments.
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Kathleen M. Mullen Dr. James Mercurio Christopher J. Serpell Paul D. Beer Prof. 《Angewandte Chemie (International ed. in English)》2009,48(26):4781-4784
Bromide is best : The first [2]rotaxane incorporating the triazolium anion‐binding motif is prepared using bromide anion templation. Preliminary anion‐binding investigations reveal that the rotaxane exhibits the rare selectivity preference for bromide over chloride ions.
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Yoshiki Morimoto Prof. Dr. Tatsuya Okita Hitomi Kambara 《Angewandte Chemie (International ed. in English)》2009,48(14):2538-2541
The proof of the pudding : The first asymmetric total synthesis of the marine tetracyclic oxasqualenoid (+)‐omaezakianol features a convergent olefin cross‐metathesis between a monotetrahydrofuran fragment and a triepoxy alkene, and cascade oxacyclizations of a triepoxy alcohol to form the right‐hand three ether rings. The total synthesis proved the absolute configuration of (+)‐omaezakianol to be that shown.
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Zhipeng Yu Xiaohua Liu Dr. Lin Zhou Lili Lin Dr. Xiaoming Feng Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(28):5195-5198
Two activations are better than one : The chiral bifunctional guanidine 1 , which features an amino amide backbone, catalyzes the asymmetric Michael addition of a range of substrates and gives products with excellent stereoselectivities. The method also allows the efficient synthesis of optically pure β‐amino acid esters. Both the guanidine group and the NH proton of the amide were important for the dual activation.