39,049 results match your criteria Angewandte Chemie International Edition [Journal]


pH-Responsive Pillar[6]arene-based Water-Soluble Supramolecular Hexagonal Boxes.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Tel Aviv University, School of Chemistry, Ramat Aviv, 69978, Tel Aviv, ISRAEL.

We describe the preparation of the first water-soluble pH-responsive supramolecular hexagonal boxes (SHBs) based on multiple charge-assisted hydrogen bonds between peramino-pillar[6]arenes 2 with the molecular "lid" mellitic acid (1a). The interaction between 2 and 1a, as well as the other "lids" pyromellitic and trimesic acids (1b and 1c, respecively) were studied by a combination of experimental and computational methods. Interestingly, the addition of 1a to the complexes of the protonated form of pillar[6]arene 2, i. Read More

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http://dx.doi.org/10.1002/anie.201900217DOI Listing
February 2019

Kinetic Resolution and Dynamic Kinetic Resolution of Chromene via Rh-Catalyzed Asymmetric Hydroarylation.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Southern University of Science and Technology, Department of Chemistry, 1088 Xueyuan Blvd., 518055, Shenzhen, CHINA.

A highly efficient kinetic resolution and dynamic kinetic resolution of chromene is reported for the first time via a Rh-catalyzed asymmetric hydroarylation pathway. This newly developed approach offers a versatile access of various chiral 2,3-diaryl-chromenes containing two vicinal stereogenic centers as well as the recovered chiral flavenes in high yields with excellent ee (s factor is up to 532). Particularly noteworthy is that this strategy can be further extended to the establishment of a dynamic version of kinetic resolution of chromene acetals, in which it allows complete access of chiral isoflavanes and α-aryl hydrocoumarin successfully. Read More

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http://dx.doi.org/10.1002/anie.201900721DOI Listing
February 2019

Forming Benzylic Iodides Via a Nickel Catalyzed Dearomative Carboiodination Reaction of Indoles.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

University of Toronto, Dept. of Chemistry, 80 St. George Street, M5S 3H6, Toronto, CANADA.

A diastereoselective dearomative carboiodination reaction is reported. We report a novel metal-catalyzed approach to install reactive secondary benzylic iodides. Utilizing the unique reactivity of nickel, we have expanded the carboiodination reaction onto non-activated aromatic double bonds forming a previously unattainable class of iodides. Read More

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http://dx.doi.org/10.1002/anie.201900659DOI Listing
February 2019

Electron-Deficient Triborane and Tetraborane Ring Compounds: Synthesis, Structure and Bonding.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Ruprecht-Karls-Universität Heidelberg, Institut für Anorganische Chemie, Im Neuenheimer Feld 270, 69120, Heidelberg, GERMANY.

Electron-deficient small boron rings are unique in their formation of sigma- and pi-delocalized electron systems, and the avoidance of "classical" structures in terms of two-center-two-electron (2c,2e) bonds. These rings are tolerant to several skeletal electron numbers, making their redox-chemistry highly interesting. In the past decades, the synthesis of a range of stable compounds with varying electron numbers in the B3 and B4 cores was achieved. Read More

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http://dx.doi.org/10.1002/anie.201900563DOI Listing
February 2019

Second-Sphere Biomimetic Multipoint Hydrogen-Bonding Patterns to Boost CO Reduction of Iron Porphyrins.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Institut de Biologie Intégrative de la Cellule (I2BC), Institut des Sciences du Vivant Frédéric-Joliot, CEA Saclay, 91191, Gif-sur-Yvette, France.

Inspired by nature's orchestra of chemical subtleties to activate and reduce CO , we have developed a family of iron porphyrin derivatives in to which we have introduced urea groups functioning as multipoint hydrogen-bonding pillars on the periphery of the porphyrinic ring. This structure closely resembles the hydrogen-bond stabilization scheme of the carbon dioxide (CO ) adduct in the carbon monoxide dehydrogenase (CODH). We found that such changes to the second coordination sphere significantly lowered the overpotential for CO reduction in this family of molecular catalysts and importantly increased the CO binding rate while maintaining high turnover frequency (TOF) and selectivity. Read More

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http://dx.doi.org/10.1002/anie.201814339DOI Listing
February 2019

High blocking temperature of magnetization and giant coercivity in the azafullerene Tb2@C79N with a single-electron Tb-Tb bond.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Virginia Tech, UNITED STATES.

The azafullerene Tb2@C79N is found to be a single molecule magnet with a high 100-s blocking temperature of magnetization of 24 K and large coercivity. Tb magnetic moments with an easy-axis single-ion magnetic anisotropy are strongly coupled by the unpaired spin of the single-electron Tb-Tb bond. Relaxation of magnetization in Tb2@C79N below 15 K proceeds via quantum tunneling of magnetization with the characteristic time τQTM = 16462±1230 s. Read More

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http://dx.doi.org/10.1002/anie.201900943DOI Listing
February 2019

Inducing Enantioselectivity in a Dynamic Catalyst by Supramolecular Interlocking.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

GERMANY.

Supramolecular ligands offer a variety of possibilities to control selectivity in catalysis due to their non-covalent interactions with other molecules. Conceptionally, enantioselectivity can be induced by interaction of chiral additives or products with the interaction sites of a supramolecular catalyst. However, the design of such catalysts is very challenging due to the complex fusion of recognition sites and catalytically active center. Read More

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http://dx.doi.org/10.1002/anie.201901175DOI Listing
February 2019

Polymer Dispersity Control via Organocatalyzed Living Radical Polymerization.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Nanyang Technological University, School of Physical and Mathematical Sciences, 21 Nanyang Link, 637371, SINGAPORE.

Molecular weight distribution of polymer, termed dispersity (Đ), is a fundamental key parameter for determining polymer material properties. This paper reports a novel approach for controlling Đ, exploiting a temperature-selective radical generation in organocatalyzed living radical polymerization. The polymers with tailored Đ were synthesized in a batch system without the assistance of an external pump. Read More

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http://dx.doi.org/10.1002/anie.201814573DOI Listing
February 2019

Superelectrophilicity of 1,2-Azaborine: Formation of Xenon and Carbon Monoxide Adducts.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.

The BN analogue of ortho-benzyne, 1,2-azaborine, is shown to bind carbon monoxide and a xenon atom under matrix isolation conditions, demonstrating its strongly Lewis acidic superelectrophilic nature. The Lewis acid-base complexes involving CO and Xe can be cleaved photochemically and reformed by mildly annealing the matrices. The interaction energy of 1,2-azaborine with Xe is 3 kcal mol according to quantum chemical computations, and is similar to that of the superelectrophilic carbene difluorovinylidene. Read More

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http://dx.doi.org/10.1002/anie.201813503DOI Listing
February 2019

The Wolff-Rearrangement Reaction of Oxidatively Generated α-Oxo Gold Carbenes: An Effective Approach to Silylketenes.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

UCSB, Chemistry and Biochemistry, Dept of Chemistry and Biochemistry, 93111, SANTA BARBARA, UNITED STATES.

Gold-catalyzed oxidations of alkynes by N-oxides offer a direct access to reactive α-oxo gold carbene intermediates from benign and readily available alkynes instead of hazardous diazo carbonyl compounds. Despite various versatile synthetic methods developed based on this strategy, one of the hallmarks of α-oxo carbene/carbenoid chemistry, i.e. Read More

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http://dx.doi.org/10.1002/anie.201814018DOI Listing
February 2019

Hybrid Organic-Inorganic Thermoelectric Materials and Devices.

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

Wenzhou University, Nano-materials & Chemistry Key Laboratory, Xueyuan Middle Road, 325027, Wenzhou, CHINA.

Hybrid organic-inorganic materials have been considered as a new candidate in the field of thermoelectric materials from the last decade due to their great potential to enhance the thermoelectric performance by utilizing the low thermal conductivity of organic materials and the high Seebeck coefficient, and high electrical conductivity of inorganic materials. Herein, we provide an overview of interfacial engineering in the synthesis of various organic-inorganic thermoelectric hybrid materials, along with the dimensional design for tuning their thermoelectric properties. Interfacial effects are examined in terms of nanostructures, physical properties and chemical doping between the inorganic and organic components. Read More

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http://dx.doi.org/10.1002/anie.201901106DOI Listing
February 2019

A Molecular Cable Car for Transmembrane Ion Transport.

Authors:
Alberto Credi

Angew Chem Int Ed Engl 2019 Feb 20. Epub 2019 Feb 20.

CLAN-Center for light activated nanostructures, Università di Bologna and Consiglio Nazionale delle Ricerche, Via Gobetti 101, 40129, Bologna, Italy.

The controlled transport of molecular and ionic substrates across bilayer membranes is a fundamental task for the operation of living organisms. It is also a highly fascinating and demanding challenge for artificial molecular machines. The recent report of a synthetic transmembrane molecular shuttle that can transport potassium ions selectively down a gradient in a liposomal system makes a small but significant step towards this goal. Read More

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http://dx.doi.org/10.1002/anie.201814333DOI Listing
February 2019

Resonance-Mediated Below-Threshold Delayed Photoemission and Non-Franck-Condon Photodissociation of Cold Oxyallyl Anions.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

University of California, San Diego, Chemistry and Biochemistry, 9500 Gilman Drive, 92093-0340, La Jolla, UNITED STATES.

The photoexcitation of cold oxyallyl anions was studied below the adiabatic detachment threshold at a photon energy of 1.60 eV. Photodetachment was observed through two product channels, delayed electron emission from a long-lived anionic state and dissociative photodetachment via absorption of a second photon. Read More

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http://dx.doi.org/10.1002/anie.201900386DOI Listing
February 2019

A Main-Group Element Radical Based One-Dimensional Magnetic Chain.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

Nanjing University, Chemistry, Xianlin Ave 163, 210023, Nanjing, CHINA.

The first main-group element radical based one-dimensional magnetic chain (1K)n was realized by one-electron reduction of the pyridinyl functionalized borane 1 with elemental potassium in THF in the absence of 18-crown-6 (18-c-6). The electron spin density of (1K)n mainly resides at the boron centers with a considerable contribution from central benzene and pyridine moieties. The spin centers exhibit an antiferromagnetic interaction as demonstrated by magnetic measurements and theoretical calculations. Read More

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http://dx.doi.org/10.1002/anie.201901177DOI Listing
February 2019

Achieving High Affinity and Selectivity for Asymmetric Dimethylarginine by Putting a Lid on a Box.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

UNC Chapel Hill, Dept. of Chemistry, CB 3290, 27599, Chapel Hill, UNITED STATES.

The methylation states of Lys and Arg represent a particularly challenging set of targets to distinguish selectively in water using synthetic receptors. To date, Kme3 is the only post translational modification (PTM) of the eight possible methylation states of Lys and Arg that can be recognized selectively. Here we report the first synthetic receptor capable of selectively recognizing Rme2a. Read More

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http://dx.doi.org/10.1002/anie.201814645DOI Listing
February 2019

Reaction of Nitrogen-Radicals with Organometallics Under Ni-Catalysis: N-Arylations and Amino-Functionalization Cascades.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

The University of Manchester, School of Chemistry, Oxford Road, M13 9PL, Manchester, UNITED KINGDOM.

Here we report a strategy for the generation of nitrogen-radicals by ground-state single electron transfer with organyl-Ni(I) species. Depending on the philicity of the N-radical, two types of processes have been developed. In the case of nucleophilic aminyl radicals direct N-arylation with aryl organozinc, organoboron and organosilicon reagents was achieved. Read More

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http://dx.doi.org/10.1002/anie.201900510DOI Listing
February 2019

Ligand-Protected "Golden Fullerene": the Dipyridylamido Au32 8+ Nanocluster.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

Tsinghua University, Chemistry Department, 1 Tsinghua Yuan, Haidian District, 100084, Beijing, CHINA.

A "golden fullerene" Au32 cluster has been synthesized with amido and phosphine ligands as the protecting agents. Single crystal X-ray structural analysis reveals that this gold nanocluster [Au32(Ph3P)8(dpa)6] (SbF6)2 (Hdpa = 2, 2'-dipyridylamine) has a stable pseudo-Ih Au328+ core with S6 symmetry, which features an Au12@Au20 Keplerate cage co-protected by Ph3P and dpa ligands. Quantum chemical studies elucidate the nature of the special stability of this cluster and suggest that it is electronically stabilized via metal-ligand interaction. Read More

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http://dx.doi.org/10.1002/anie.201901478DOI Listing
February 2019

Near-infrared quadrupolar chromophores combining three-coordinate boron-based superdonor and -acceptor units.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

Julius-Maximilians-Universitat Wurzburg, Department of Chemistry, Am Hubland, 97074, Würzburg, GERMANY.

In this work, two new quadrupolar A-π-D-π-A chromophores have been prepared featuring a strongly electron-donating diborene core and strongly electron-accepting dimesitylboryl (BMes2) and bis(2,4,6-tris(trifluoromethyl)phenyl)boryl (BFMes2) end groups. Analysis of the compounds by NMR spectroscopy, X-ray crystallography, cyclic voltammetry and UV-vis-NIR absorption and emission spectroscopy indicated that the compounds possess extended conjugated π-systems spanning their B4C8 cores. The combination of exceptionally potent π-donor (diborene) and π-acceptor (diarylboryl) groups, both based on trigonal boron, leads to very small HOMO-LUMO gaps, resulting in strong absorption in the near-IR region with maxima in THF at 840 and 1092 nm, respectively, and very high extinction coefficients of ca. Read More

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http://dx.doi.org/10.1002/anie.201900889DOI Listing
February 2019

A Dual-Stimuli-Responsive Coordination Network Featuring a Reversible Wide-Range Luminescence Tuning Behavior.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

Nankai University, Chemistry, No. 94, Weijin Road, 300071, Tianjin, CHINA.

We herein report a new coordination network that deforms in a smooth and reversible manner under either thermal or pressure stimulation. Concomitantly, the organic fluorophores coordinatively bound to the channel in a face-to-face arrangement respond to this structural deformation by finely adapting their conformation and arrangement. As a result, the material exhibits a remarkable dual-stimuli-responsive luminescence shift across almost the entire visible region: The emission color of the crystal gradually changes from cyan to green by heating and then to red by pressure compression. Read More

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http://dx.doi.org/10.1002/anie.201900190DOI Listing
February 2019

Practical and scalable kinetic resolution of BINOLs mediated by a chiral counterion.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, OX1 3TA, Oxford, UNITED KINGDOM.

BINOLs are valuable and widely used building blocks, chiral ligands and catalysts that are effective across a remarkable range of different chemical transformations. Here we demonstrate that an ammonium salt catalysed kinetic resolution of racemic BINOLs with benzyl tosylate proceeds with s up to 46. This is a scalable and practical process that can be applied across >30 different C2- and non-C2-symmetric BINOLs. Read More

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http://dx.doi.org/10.1002/anie.201814381DOI Listing
February 2019

Stereoselectively Assembled MOF Host for Self-boosting Catalytic Synthesis of Carbon Hybrids.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

CHINA.

Cost-effective metal-based nanostructured hybrids have been widely dedicated to potential energy storage and conversion applications. Yet, controllably engineering the functional building blocks in flexible hierarchical structures with high reactivity, good electron conductivity and excellent structural stability remains challenging. Herein, we develop a facile methodology for the synthesis of precise carbon-confined hybrid nanostructures by stereoselective assembly accompanied with the self-boosting catalytic pyrolysis. Read More

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http://dx.doi.org/10.1002/anie.201900240DOI Listing
February 2019
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(NHC)NiIIH-Catalyzed Cross-Hydroalkenylation of Cyclopropene with Alkyne: A Straight Forward Cyclopentadiene Synthesis by NHC-NiII Assisted C-C Rearrangement.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

South University of Science and Technology of China, Department of Chemistry, No 1088,xueyuan Rd.,, Xili, Nanshan District,, 518055, Shenzhen, CHINA.

Cross-hydroalkenylation-rearrangement cascade (HARC) that using cyclopropene 1 and alkyne 2 as substrate pairs was first achieved by using a set of new [NHC-Ni(allyl)]BArF catalysts. By controlling the NHC-NiIIH relative insertion reactivity with 1 and 2, a broad scope of cyclopentadiene 3 was obtained highly selectively for the first time. The new NHC-NiII catalyst structural features were found as the keys for the success. Read More

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http://dx.doi.org/10.1002/anie.201901255DOI Listing
February 2019

A Scalable Methylamine Gas Healing Strategy for High Efficiency Inorganic Perovskite Solar Cells.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Solar cells, Songling Road 189, 266101, Qingdao, CHINA.

An easy and scalable methylamine (MA) gas healing method was realized for inorganic cesium based perovskite (CsPbX₃) layer by incorporating a certain amount of MAX (X=I or Br) initiator into the raw film. It was found that the excess MAX could accelerate the absorption rate of the MA gas into the CsPbX₃ film and quickly turn it into a liquid intermediate phase. Through the healing process, a high uniform and high crystallinity CsPbX₃ film with enhanced device performance was achieved. Read More

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http://dx.doi.org/10.1002/anie.201814024DOI Listing
February 2019

Radionuclide-Activated Nanomaterials and Their Biomedical Applications.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

University of Wisconsin - Madison, Department of Radiology, 1111 Highland Avenue, Room 7137, 53705, Madison, UNITED STATES.

Radionanomedicine, or the use of radiolabeled nanoparticles in nuclear medicine, has attracted much attention in the last decades. Since the discovery of Cerenkov radiation and its employment in Cerenkov luminescence imaging, the combination of nanomaterials and Cerenkov radiation emitters is revolutionizing the way nanomaterials are perceived in the field: from simple inert carriers of radioactivity to activatable nanomaterials for both diagnostic and therapeutic applications. Herein, we will provide a comprehensive review on the types of nanomaterials that have been used to interact with Cerenkov radiation, gamma and beta scintillation of radionuclides as well as on the biological applications of that synergistic combination. Read More

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http://dx.doi.org/10.1002/anie.201900594DOI Listing
February 2019

Rapid, traceless, Ag(I)-promoted macrocyclization of peptides possessing an N-terminal thioamide.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

University of Melbourne, School of Chemistry, 30 Flemington Rd., VIC 3095, Parkville, AUSTRALIA.

Peptide macrocyclization is often a slow process, plagued by epimerization and cyclodimerization. Herein we describe a new method for peptide macrocyclization employing the Ag(I)-promoted transformation of peptide thioamides. The Ag(I) has a dual function: chemselectively activating the thioamide and tethering the N-terminal thioamide to the C-terminal carboxylate. Read More

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http://dx.doi.org/10.1002/anie.201900243DOI Listing
February 2019

Full Dissolution of Li2S8 to Li2S in Safe Eutectic Solvent for Rechargeable Lithium-Sulfur Batteries.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Columbia University, Applied Physics and Applied Mathematics, Cambridge, MA, 02215, United States, 10027, New York, UNITED STATES.

Lithium-sulfur battery is an attractive option for next-generation energy storage due to its much higher theoretical energy density than state-of-the-art lithium-ion batteries. However, the massive volume changes of the sulfur cathode and the uncontrollable deposition of Li2S2/Li2S significantly deteriorate cycling life and increase voltage polarization. To address these challenges, we develop an ε-caprolactam/acetamide based eutectic-solvent electrolyte, which can dissolve all lithium polysulfides and lithium sulfide (Li2S8-Li2S). Read More

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http://dx.doi.org/10.1002/anie.201812611DOI Listing
February 2019

Pd-Catalyzed Selective Carbonylation of gem-Difluoroalkenes: A Practical Synthesis of Difluoromethylated Esters.

Angew Chem Int Ed Engl 2019 Feb 19. Epub 2019 Feb 19.

Leibniz-Institut für Katalyse, Homogeneous Catalysis, Albert-Einstein-Straße 29a, 18059, Rostock, GERMANY.

The first catalyst system for the alkoxycarbonylation of gem-difluoroalkenes is described. This novel catalytic transformation proceeds in the presence of Pd(acac)2/1,2-bis((di-tert-butylphosphan-yl)methyl)benzene (btbpx) (L4) and allows for an efficient and straightforward access to a wide range of difluoromethylated esters in high yields with good to excellent regioselectivities. The synthetic utility of the protocol is showcased in the practical synthesis of a Cyclandelate analogue using this methodology as the key step. Read More

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http://dx.doi.org/10.1002/anie.201813801DOI Listing
February 2019

Decarboxylation with Carbon Monoxide: The Direct Conversion of Carboxylic Acids into Potent Acid Triflate Electrophiles.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

McGill University, Chemistry, 801 Sherbrooke St. W., H3A0B8, Montreal, CANADA.

We report a new strategy for the conversion of carboxylic acids into potent acid triflate electrophiles. The reaction involves oxidative carbonylation of carboxylic acids with I2 in the presence of AgOTf, and is postulated to proceed via acyl hypoiodites that react with CO to form acid triflates. Coupling this chemistry with subsequent trapping with arenes offers a mild, room temperature approach to generate ketones directly from broadly available carboxylic acids without the use of corrosive and reactive Lewis or Bronsted acid additives, and instead from compounds that are all by themselves available, stable, and highly functional group compatible. Read More

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http://dx.doi.org/10.1002/anie.201814660DOI Listing
February 2019

Lutidine-Based Chiral Pincer Mn Catalysts for Enantioselective Hydrogenation of Ketones.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Shanghai Institute of Organic Chemistry, CHINA.

A series of Mn(I) complexes containing lutidine-based chiral pincer ligands with modular and tunable structures has been developed. The complex features unprecedentedly high activity (up to 9800 TON), broad substrate scope (81 examples), good functional group tolerance, and excellent enantioselectivity (85~98% ee) in the hydrogenation of various ketones, which are rare in earth-abundant metal catalyzed hydrogenation. The utilities of the protocol have been demonstrated in the asymmetric synthesis of a variety of key intermediates of chiral drugs. Read More

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http://doi.wiley.com/10.1002/anie.201814751
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http://dx.doi.org/10.1002/anie.201814751DOI Listing
February 2019
5 Reads

Harnessing Bottom-up Self-Assembly to Position Five Distinct Components in an Ordered Porous Framework.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Fudan University, Department of Chemistry, 220 Handan Road, 200433, Shanghai, CHINA.

Positioning a diverse set of building blocks in a well-defined array allows for cooperativity amongst them and the systematic programming of functional properties. Extending this concept to porous metal-organic frameworks (MOFs) is challenging since installing multiple components in a well-ordered framework requires careful design of the lattice topology, judicious selection of building blocks, and precise control of the crystallization parameters. In this work, we report how we have met these challenges to prepare the first quinary MOF structure, FDM-8, by bottom-up self-assembly. Read More

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http://dx.doi.org/10.1002/anie.201900863DOI Listing
February 2019

The Dual Role of Benzophenone in Visible-Light/Nickel Photoredox-Catalyzed C-H Arylations: Hydrogen-Atom Transfer and Energy Transfer.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany.

A dual catalytic protocol for the direct arylation of non-activated C(sp )-H bonds has been developed. Upon photochemical excitation, the excited triplet state of a diaryl ketone photosensitizer abstracts a hydrogen atom from an aliphatic C-H bond. This inherent reactivity was exploited for the generation of benzylic radicals which subsequently enter a nickel catalytic cycle, accomplishing the benzylic arylation. Read More

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http://dx.doi.org/10.1002/anie.201901327DOI Listing
February 2019

Cyanidosilicates - Synthesis and Structure.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

GERMANY.

Starting from fluoridosilicate precursors in neat cyano-trimethylsilane, Me3Si-CN, a series of different ammonium salts [R3NMe]+ (R = Et, nPr, nBu) with the novel [SiF(CN)5]2- and [Si(CN)6]2- dianions were synthesized in facile, temperature controlled F- / CN- exchange reactions. Utilizing decomposable, non-innocent cations such as [R3NH]+, it was possible to generate metal salts of the type M2[Si(CN)6] (M+ = Li+, K+) via neutralization reactions with the corres¬ponding metal hydroxides. The ionic liquid [BMIm]2[Si(CN)6] (m. Read More

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http://dx.doi.org/10.1002/anie.201901173DOI Listing
February 2019

Dynamics of the Bulk Hydrated Electron from Many-Body Wave-Function Theory.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.

The structure of the hydrated electron is a matter of debate as it evades direct experimental observation owing to the short life time and low concentrations of the species. Herein, the first molecular dynamics simulation of the bulk hydrated electron based on correlated wave-function theory provides conclusive evidence in favor of a persistent tetrahedral cavity made up by four water molecules, and against the existence of stable non-cavity structures. Such a cavity is formed within less than a picosecond after the addition of an excess electron to neat liquid water, with less regular cavities appearing as intermediates. Read More

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http://dx.doi.org/10.1002/anie.201814053DOI Listing
February 2019

Spotlights on our sister journals: Angew. Chem. Int. Ed. 9/2019.

Authors:

Angew Chem Int Ed Engl 2019 Feb;58(9):2550-2554

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http://dx.doi.org/10.1002/anie.201980913DOI Listing
February 2019

First Total Synthesis of (-)-Alstofolinine A via Cascade Furan Oxidation/rearrangement and Indole Nucleophilic Cyclization.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

National Institute of Biological Sciences, chemistry center, #7 science park rd, zhongguancun life science park, China, 102206, beijing, CHINA.

A novel reaction cascade of Aza-Achmatowicz rearrangement followed by indole nucleophilic cyclization was developed to generate the common indole-fused [3.3.1] core of the Macroline family alkaloids. Read More

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http://dx.doi.org/10.1002/anie.201900156DOI Listing
February 2019
11.261 Impact Factor

Asymmetric Total Syntheses of the Akuammiline Alkaloids (-)-Strictamine and (-)-Rhazinoline.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

CHINA.

Strictamine and rhazinoline are representative methanoquinolizidine-containing akuammiline alkaloids that possess different stereochemistry at the C16 position. A unified approach to the enantioselective total syntheses of these two molecules is described. The key steps in this synthesis include a photocatalytic intra/intermolecular type II radical cascade reaction, a Tsuji-Trost allylation, a palladium- or nickel-mediated cyclization, and a late-stage intramolecular N-alkylation reaction. Read More

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http://dx.doi.org/10.1002/anie.201901074DOI Listing
February 2019

Activating Inert, Nonprecious Perovskite Matrix by Iridium Dopants for Efficient Oxygen Evolution Reaction in Acid.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

CHINA.

Simultaneous realization of improved activity, enhanced stability and reduced cost remains a desirable yet challenging goal in the search of oxygen evolution electrocatalysts in acid. Here we report the identification of iridium-incorporated strontium titanates (Ir-STO) as active and stable, low-iridium perovskite electrocatalysts for the oxygen evolution reaction (OER) in acid. The Ir-STO contains 57 wt% less iridium relative to the benchmark catalyst IrO2, but it exhibits more than 10 times higher catalytic activity for OER than the latter. Read More

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http://dx.doi.org/10.1002/anie.201900796DOI Listing
February 2019

Nickel-Catalyzed Carbofluoroalkylation of 1,3-Enynes to Access Structurally Diverse Fluoroalkylated Allenes.

Angew Chem Int Ed Engl 2019 Feb 17. Epub 2019 Feb 17.

University of Science and Technology of China, Chemistry, 96 Jinzhai Road, 230026, Hefei, CHINA.

A nickel-catalyzed 1,4-carbofluoroalkylation of 1,3-enynes to access structurally diverse fluoroalkylated allenes has been established. This method has demonstrated high catalytic reactivity, mild conditions, broad substrates scope and excellent functional group tolerance. The key to success is the use of nickel catalyst to generate different kinds of fluoroalkyl radicals from readily available and structurally diverse fluoroalkyl halides to access 1,4-difunctionalization of 1,3-enynes via a radical relay. Read More

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http://dx.doi.org/10.1002/anie.201813184DOI Listing
February 2019

Strange Case of Sig. Volta and Mr. Nicholson. How Electrochemistry Developed as a Consequence of an Editorial Misconduct.

Authors:
Luigi Fabbrizzi

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Universita di Pavia, Dipartimento di Chimica, via Taramelli 12, 27100, Pavia, ITALY.

This historical review tells the colourful history of the invention of the pile by Alessandro Volta and of the subsequent discovery by William Nicholson of the electrolysis of water carried out with the Voltaic pile (1800). Indeed, due to the dissemination of Volta's paper among London scientists favoured by an incorrect behaviour of the President of the Royal Society, the article by Nicholson was published months before the publication of the Volta's letter. The outstanding news that electricity could be generated by a simple and easy to build instrument (the pile) was printed also by daily newspapers, which favoured its spreading all over Europe and stimulated a multitude of enthusiast practitioners and amateurs to construct their own pile and to carry out the electrical decomposition of a variety of aqueous electrolytes. Read More

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http://dx.doi.org/10.1002/anie.201813519DOI Listing
February 2019

Opto-epigenetic modulation of DNA methylation with a photo-responsive small-molecule approach.

Angew Chem Int Ed Engl 2019 Feb 17. Epub 2019 Feb 17.

University College London, Department of Chemistry, 20 Gordon Street, WC1H 0AJ, London, UNITED KINGDOM.

Controlling the functional dynamics of DNA within living cells is essential in biomedical research. Epigenetic modifications such as DNA methylation play a key role in this process. Controlled DNA methylation editing can be attained via genetic means. Read More

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http://dx.doi.org/10.1002/anie.201901139DOI Listing
February 2019

A Universal, Isothermal DNA Amplification Method based on RNA-Guided Cas9 Nickase.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

CHINA.

We have developed an ingenious method, termed Cas9 nickase-based amplification reaction (Cas9nAR), to amplify a target fragment from genomic DNA at a constant temperature of 37 degrees Celsius. Cas9nAR employs a sgRNA:Cas9n complex with single-strand nicking property, a strand-displacing DNA polymerase, and two primers bearing the cleavage sequence of Cas9n, to promote repetitive rounds of DNA replication via cyclic processes of priming, extension, nicking, and displacement reactions. Cas9nAR exhibits a zeptomolar limit of detection (2 copies in 20 uL of reaction system) within 60 min and a single-base discrimination capability. Read More

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http://dx.doi.org/10.1002/anie.201901292DOI Listing
February 2019

Stable Hierarchical Bimetal-Organic Nanostructures as HighPerformance Electrocatalysts for the Oxygen Evolution Reaction.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, CA, 90840, USA.

The integration of heterometallic units and nanostructures into metal-organic frameworks (MOFs) used for the oxygen evolution reaction (OER) can enhance the electrocatalytic performance and help elucidate underlying mechanisms. We have synthesized a series of stable MOFs (CTGU-10a1-d1) based on trinuclear metal carboxylate clusters and a hexadentate carboxylate ligand with a (6,6)-connected nia net. We also present a strategy to synthesize hierarchical bimetallic MOF nanostructures (CTGU-10a2-d2). Read More

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http://dx.doi.org/10.1002/anie.201813634DOI Listing
February 2019

Core-Modulation of 70-nuclei Core-Shell Silver Nanoclusters.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

Shandong University, Department of Chemistry and Chemical Engineering, Shanda South Road 27, 250100, Jinan, CHINA.

The reaction of {(HNEt3)2[Ag10(tBuC6H4S)12]}n, Ag2O, Na2MoO4 and m-methoxybenzoic acid (Hmbc) in CH3OH/CH2Cl2 led to only yellow crystals of [Ag4S4(MoO4)5@Ag66] (SD/Ag70b; SD = SunDi), but in the presence of DMF additional dark-red crystals of [Ag10@(MoO4)7@Ag60] (SD/Ag70a) were obtained. The former consists of five MoO42- wrapped by a shell of 66 Ag atoms. The latter contains a rare Ag10 kernel consisting of five tetrahedra sharing faces and edges ringed by seven MoO42- which is enclosed in a shell of 60 Ag atoms. Read More

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http://dx.doi.org/10.1002/anie.201900568DOI Listing
February 2019

First synthesis and characterisation of CH4@C60.

Angew Chem Int Ed Engl 2019 Feb 18. Epub 2019 Feb 18.

University of Southampton, School of Chemistry, Highfield, SO17 1BJ, Southampton, UNITED KINGDOM.

The endohedral fullerene CH4@C60, in which each C60 fullerene cage encapsulates a single methane molecule, has been synthesised for the first time. The key orifice contraction step, a photochemical desulfinylation of an open fullerene, was successfully completed, even though it is significantly inhibited by the presence of the endohedral molecule. The 13C NMR resonance for the cage nuclei in CH4@C60 is deshielded by Δδ = +0. Read More

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http://dx.doi.org/10.1002/anie.201900983DOI Listing
February 2019

Enhanced Circularly Polarized Luminescence from Reorganized Chiral Emitters on the Skeleton of Zeolitic Imidazolate Framework.

Angew Chem Int Ed Engl 2019 Feb 17. Epub 2019 Feb 17.

National Center for Nanoscience and Technology, Key Laboratory of Nanosystem and Hierarchical Fabrication, No.11 ZhongGuanCunBeiYiTiao, 100190, Beijing, CHINA.

Chiral zeolitic imidazolate framework (ZIF) showing circularly polarized luminescence (CPL) has been successfully achieved through a ligand-exchange approach by blending a binapthyl-derived chiral emitter with ZIF-8 rhombododecahedron nanoparticles. This approach solves a major trade-off in CPL-active materials: large luminescence dissymmetry factor (glum) always suffer from supression of luminescence efficiency, due to the magnetic and electronic dipole transition nature. Compared with the optical properties of chiral emitter in dilute solution, the obtained chiral ZIF nanomaterials showed enhanced fluorescence efficiency (from 0. Read More

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http://dx.doi.org/10.1002/anie.201900052DOI Listing
February 2019

Synthesis of Bimetallic Copper-Rich Nanoclusters Encapsulating a Linear Palladium Dihydride Unit.

Angew Chem Int Ed Engl 2019 Feb 16. Epub 2019 Feb 16.

National Dong Hwa University, Department of Chemistry, 1, section 2, University drive, 974, Hualien, TAIWAN.

The structurally precise Cu-rich hydride nanoclusters [PdCu14H2(dtc/dtp)6(C≡CPh)6] (dtc: di-butyl dithiocarbamate (1); dtp: di-isopropyl dithiophosphate (2)) were synthesized from the reaction of polyhydrido copper clusters [Cu28H15(S2CNnBu2)12]+ or [Cu20H11{S2P(OiPr)2}9] with phenyl acetylene in the presence of Pd(PPh3)2Cl2. Their structures and compositions were determined by single crystal X-ray diffraction and the results were supported by ESI-mass spectrometry. Hydride positions in 1 were confirmed by single crystal neutron diffraction. Read More

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http://dx.doi.org/10.1002/anie.201814264DOI Listing
February 2019

Exploiting Boron Coordination: B←N Bond Supports a [2+2] Photodimerization in the Solid State and Generation of a Diboron Bis-Tweezer for Benzene/Thiophene Separation.

Angew Chem Int Ed Engl 2019 Feb 15. Epub 2019 Feb 15.

University of Iowa, Chemistry, E555 Chem Bldg, 52245, Iowa City, UNITED STATES.

B←N coordination supports a [2+2] photodimerization in the solid state. The bond is defined by an orthogonal interaction between stilbazole and a phenylboronic ester to enable a stereocontrolled and rapid photoreaction. The cyclobutane photoproduct affords a novel diboron bis-tweezer adduct that is used to separate a mixture of benzene and thiophene upon crystallization. Read More

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http://dx.doi.org/10.1002/anie.201812174DOI Listing
February 2019

Dearomatization of 3-Nitroindoles via a Phosphine-catalyzed Enantioselective [3+2] Annulation Reaction.

Angew Chem Int Ed Engl 2019 Feb 15. Epub 2019 Feb 15.

SAUDI ARABIA.

A dearomatization process of 3-nitroindoles via a chiral phosphine-mediated [3+2] annulation reaction has been developed. This method makes use of readily available 3-nitroindoles as an aromatic feedstock and quickly delivers a wide range of cyclopentaindoline alkaloid scaffolds in a highly enantioselective manner. Notably, this is the first time that phosphine-triggered cyclization has been utilized in a dearomatization process. Read More

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http://dx.doi.org/10.1002/anie.201900248DOI Listing
February 2019

Complex formation of the tetracycline-binding aptamer investigated by specific cross-relaxation under DNP.

Angew Chem Int Ed Engl 2019 Feb 15. Epub 2019 Feb 15.

Goethe-Universität Frankfurt, Biochemie, Chemie und Pharmazie, Max-von-Laue-Str. 7, N140/014, 60435, Frankfurt, GERMANY.

While dynamic nuclear polarization (DNP) under magic-angle spinning (MAS) is generally a powerful method capable of greatly enhancing the sensitivity of solid-state NMR, the displacement of nuclear spin polarization far from thermal equilibrium (i.e., hyperpolarization) also gives rise to peculiar spin dynamics. Read More

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http://dx.doi.org/10.1002/anie.201811941DOI Listing
February 2019

Efficient access to deuterated and tritiated nucleobase pharmaceuticals and oligonucleotides using hydrogen isotope exchange.

Angew Chem Int Ed Engl 2019 Feb 15. Epub 2019 Feb 15.

CEA Saclay, DSV, route nationnal, France, 91191, Gif-sur-Yvette, FRANCE.

A general approach for the nucleobase derivatives hydrogen isotope exchange is described. Catalyzed by ruthenium nanoparticles, using mild reaction conditions and involving D2 or T2 as isotopic sources, this reaction possesses a wide substrate scope and a high solvent tolerability. This novel method facilitates the convenient access to essential diagnostic tools in drug discovery and development: tritiated pharmaceuticals with high specific activities and deuterated oligonucleotides suitable to be used as internal standards for LC-MS quantification. Read More

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http://dx.doi.org/10.1002/anie.201813946DOI Listing
February 2019
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