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Chemical News - 31 maggio, 2019 - 01:45

Exploiting Natural Complexity: Synthetic Terpenoid-Alkaloids by Regioselective and Diastereoselective Hydroaminoalkylation Catalysis

Articles from Wiley - 31 maggio, 2019 - 00:00

Tantalizing complexity: an in situ Ta-catalyzed method for hydroaminoalkylation using naturally occurring terpene substrates to generate terpenoid-alkaloid products is reported. This reaction uses alkyltantalum precursors in combination with modular urea ligands for highly regio- and diastereoselective transformations. Products can all be purified using a simple filtration protocol, and crystallography data confirms the formation of a single diastereomer and no racemization of enantioenriched terpene substrates.

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Rebecca C. DiPucchio, Dr. Sorin-Claudiu Rosca, Gayathri Athavan, Prof. Laurel L. Schafer
doi.org/10.1002/cctc.201900398

Ruthenium Nanoparticles for Catalytic Water Splitting

Articles from Wiley - 31 maggio, 2019 - 00:00

Breaking it down: Catalysts for the hydrogen and oxygen evolution reactions are key components of new sustainable energy conversion schemes based on water splitting and sunlight. This review covers the most significant developments in ruthenium-based nanoparticles as catalysts for these processes, focusing on factors that govern their performance.

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Dr. Jordi Creus, Dr. Jonathan De Tovar, Dr. Nuria Romero, Dr. Jordi García-Antón, Dr. Karine Philippot, Dr. Roger Bofill, Dr. Xavier Sala
doi.org/10.1002/cssc.201900393

Dicarboxylate-Induced Structural Diversity of Luminescent Zn(II)/Cd(II) Metal-Organic Frameworks Based on the 2,5-Bis(4-pyridyl)thiazolo[5,4-<i>d</i>]thiazole Ligand

Articles from Wiley - 31 maggio, 2019 - 00:00

Auxiliary dicarboxylate ligands confer structural diversity upon nine Zn(II)/Cd(II) MOFs based on 2,5-bis(4-pyridyl)thiazolo[5,4-d]thiazole and further change their luminescence properties.

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Zhi-Wei Zhai, Shuang-Hua Yang, Peng Luo, Lin-Ke Li, Chen-Xia Du, Shuang-Quan Zang
doi.org/10.1002/ejic.201900259

Mechanistic Studies on the Reaction of [Fe<sup>III</sup>(edta)(H<sub>2</sub>O)]<sup>-</sup> with Piloty′s Acid as Source for HNO

Articles from Wiley - 31 maggio, 2019 - 00:00

In earlier work, the reaction of [FeII(edta)(H2O)]2- with ·NO(g) was studied as a trap for ·NO(g) and found to be very efficient. The formed nitrosyl complex was shown to have substantial FeIII-NO-, i.e. nitroxyl, character. We have now used [FeIII(edta)(H2O)]- as starting material and studied the reaction with Piloty's acid as source for HNO/NO- (nitroxyl) to produce the same reaction product.

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André Muthig, Justyna Polaczek, Rudi van Eldik
doi.org/10.1002/ejic.201900261

Periodic Mesoporous Organosilicas from Polyion Complex Micelles - Effect of Organic Bridge on Nanostructure

Articles from Wiley - 31 maggio, 2019 - 00:00

A new family of periodic mesoporous organosilicas, PICPMOs, is obtained, in the presence of polyion complex (PIC) micelles, by hydrolysis-condensation of organosilanes containing various organic bridging units influencing the nanostructure and physical properties of the materials.

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Albane Birault, Emilie Molina, Philippe Trens, Didier Cot, Guillaume Toquer, Nathalie Marcotte, Carole Carcel, John R. Bartlett, Corine Gérardin, Michel Wong Chi Man
doi.org/10.1002/ejic.201900487

Salalens and Salans Derived from 3-Aminopyrrolidine: Aluminium Complexation and Lactide Polymerisation

Articles from Wiley - 31 maggio, 2019 - 00:00

A series of AlIII complexes with salan and salalen ligands were prepared. These were trialled for the controlled ROP of rac-LA. The salan complexes were shown to be significantly more active for the polymerisation.

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Luke Britton, Daniel Ditz, James Beament, Paul McKeown, Helena C. Quilter, Kerry Riley, Mary F. Mahon, Matthew D. Jones
doi.org/10.1002/ejic.201900417

Carboxylate Groups in a 90° Arrangement: 1,3-Allenedicarboxylic Acid and Its Alkali Metal and Thallium(I) Coordination Compounds

Articles from Wiley - 31 maggio, 2019 - 00:00

With a torsion angle of 90°, the allene dicarboxylate is a structurally unique dianion; in the crystal structure of its sodium compound, the cation has unprecedented “seesaw” coordination geometry.

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Christoph Kahrs, Marc Schmidtmann, Mathias S. Wickleder, Jens Christoffers
doi.org/10.1002/ejic.201900520

The Chemo- and Stereoselective Formation of Pallado- and Platinocryptophanes

Articles from Wiley - 31 maggio, 2019 - 00:00

Metallocryptophanes were assembled from optically pure cyclotricyanotribenzylene (CTB) 1 and [M(dppp)(OTf)2] (M = Pd and Pt), and their chiroptical properties were studied experimentally and theoretically, providing evidence of ICD effects. As shown by 1H NMR spectroscopy and ESI mass spectrometry, the reaction proceeds stereoselectively and chemoselectively when a second CTB is involved in the self-assembly.

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Astrid Schaly, Michel Meyer, Jean-Claude Chambron,, Marion Jean, Nicolas Vanthuyne, Emmanuel Aubert, Enrique Espinosa, Nathalie Zorn, Emmanuelle Leize-Wagner
doi.org/10.1002/ejic.201900230

Exploration of the Luminescence Properties of Organic Phosphate Salts of 3-Quinoline- and 5-Isoquinolineboronic Acid

Articles from Wiley - 31 maggio, 2019 - 00:00

A series of three new crystalline molecular salts was prepared from quinoline boronic acids and organic phosphates. The supramolecular networks in the solid state and their luminescence behavior were examined.

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Glenda Y. Ruelas-Alvarez, A. Jaquelin Cárdenas-Valenzuela, Adriana Cruz-Enríquez, Herbert Höpfl, José J. Campos-Gaxiola, Mario A. Rodríguez-Rivera, Braulio Rodríguez-Molina
doi.org/10.1002/ejic.201900244

Palladium-Catalyzed Carboxy-Alkynylation of Propargylic Amines Using Carbonate Salts as Carbon Dioxide Source

Articles from Wiley - 31 maggio, 2019 - 00:00

A palladium-catalyzed multicomponent reaction of propargylic amines, alkynyl bromides and cesium hydrogen carbonate to access oxazolidinones is reported. In contrast to previous reports, only a slight excess of cesium hydrogen carbonate is used as surrogate of carbon dioxide.

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Phillip D. G. Greenwood, Jerome Waser
doi.org/10.1002/ejoc.201900500

The Selective <i>N</i>-Functionalization of Indoles via <i>aza</i>-Michael Addition in the Ligand Sphere of a Chiral Nickel(II) Complex: Asymmetric Synthesis of (<i>S</i>)-1<i>H</i>-Indole-Alanine Derivatives

Articles from Wiley - 31 maggio, 2019 - 00:00

No C3-alkylation! The first protocol for the asymmetric synthesis of 2-amino-3-(1H-indol-1-yl)propanoic acids via the selective aza-Michael addition of a C=C double bond to indoles taking place in the ligand sphere of a chiral nickel(II) complex is reported.

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Vladimir A. Larionov, Tat'yana F. Savel'yeva, Michael G. Medvedev, Nadezhda V. Stoletova, Alexander F. Smol'yakov, Zalina T. Gugkaeva, Thomas Cruchter, Victor I. Maleev
doi.org/10.1002/ejoc.201900650

Photocatalyzed Generation of Nitrosocarbonyl Intermediates Under Solar Light Irradiation

Articles from Wiley - 31 maggio, 2019 - 00:00

Tetrabutylammonium decatungstate (TBADT) promoted the oxidation of hydroxamic acids to nitrosocarbonyl intermediates. The reaction took place under aerobic conditions upon irradiation with solar light. The thus generated nitrosocarbonyls were efficiently trapped with reactive dienes to afford the corresponding Hetero Diels-Alder (HDA) cycloadducts in good yields.

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Teresa Basile, Luca Capaldo, Davide Ravelli, Paolo Quadrelli
doi.org/10.1002/ejoc.201900596

Continuous Flow Synthesis of Highly Substituted Tetrahydrofurans

Articles from Wiley - 31 maggio, 2019 - 00:00

Under continuous flow conditions, the diastereoselective synthesis of a broad range of 2,3,5-trisubstituted tetrahydrofurans has been developed. Compared to the initial batch synthesis both yields and selectivities with respect to different substituents in the 2,5-position were improved and reaction times significantly reduced.

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Patrick Hoffmeyer, Christoph Schneider
doi.org/10.1002/ejoc.201900421

Mild, Metal-Free and Protection-Free Transamidation of N-Acyl-2-piperidones to Amino Acids, Amino Alcohols and Aliphatic Amines and Esterification of N-Acyl-2-piperidones

Articles from Wiley - 31 maggio, 2019 - 00:00

A highly selective mild and metal-free protocol for transamidation of N-acyl piperidones to unprotected amino acids, amino alcohols and other aliphatic amines at short reaction times (30-45 min), with no additional base and at neat condition. Esterification of N-acyl piperidones with aliphatic alcohols at 85 °C. Amide bond twist, τ = -20.39° and pyramidalization, χN = -11.73°.

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Muthuraman Subramani, Saravana Kumar Rajendran
doi.org/10.1002/ejoc.201900517

Alkene Assisted Homolysis of the Si-H, Ge-H, and Sn-H Bond: New Examples of Molecule Assisted Homolysis (MAH)

Articles from Wiley - 31 maggio, 2019 - 00:00

Mix tris(trimethylsilyl) silane with an alkene, wait and isolate the hydrosilylation product in good yield. Where is the initiator? What′s doing the silane with the alkene? The Si-H hydrogen is transferred to the alkene to give two radicals in a most slow reaction, initiating a most efficient radical chain reaction. Analogous hydrogermylation and hydrostannylation are reported as well.

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Ursula Biermann, Gerd Klaassen, Rainer Koch, Jürgen O. Metzger
doi.org/10.1002/ejoc.201900363

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