slideshow 16 slideshow 1 slideshow 2 slideshow 3 slideshow 4 slideshow 5 slideshow 6 slideshow 7 slideshow 8 slideshow 0 slideshow 9 slideshow 10 slideshow 11 slideshow 12 slideshow 13 slideshow 14 slideshow 15

Articles from Wiley

Condividi contenuti
The latest chemistry from ChemPubSoc Europe and Wiley-VCH
Aggiornato: 7 settimane 5 giorni fa

Frontispiece: Tuning the Energy Transfer Efficiency between Ce<sup>3+</sup> and Ln<sup>3+</sup> Ions (Ln=Tm, Sm, Tb, Dy) by Controlling the Crystal Phase of NaYF<sub>4</sub> Nanocrystals

25 gennaio, 2017 - 00:00

 Tuning the Energy Transfer Efficiency between Ce3+ and Ln3+ Ions (Ln=Tm, Sm, Tb, Dy) by Controlling the Crystal Phase of NaYF4 Nanocrystals

Nanocrystals The control of the phase of the nanocrystals can tune the energy transfer efficiency between Ce3+ and Ln3+ ions in NaYF4 (Ln=Tm, Sm, Tb, Dy). Cubic-phase Ce3+/Ln3+-doped NaYF4 particles display strong emissions of Ln3+ ions compared to hexagonal-phase particles, despite the latter possessing larger particle size. The difference is attributed to the different crystal-field environment experience by Ce3+ ions. For more details, see the Communication by V. Mahalingam et al. on page 994 ff.

[Frontispiece]
Venkata N. K. B. Adusumalli, Heramba V. S. R. M. Koppisetti, Sagar Ganguli, Shyam Sarkar, Venkataramanan Mahalingam
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201780562. Read article

Frontispiece: Peptide-Based Molecular Hydrogels as Supramolecular Protein Mimics

25 gennaio, 2017 - 00:00

 Peptide‐Based Molecular Hydrogels as Supramolecular Protein Mimics

Peptidic hydrogelators In their Minireview on page 981 ff., J. F. Miravet, R. V. Ulijn, B. Escuder et al. discuss recent advances in the design, synthesis, and application of low molecular-weight peptidic hydrogelators. Prevalent types of these structures include N-capped amino acid residues, bolamphiphilic peptides, and amphipathic peptides, whereas hydrophobic effects, the Hofmeister effect, and tunable ionization influence their aggregation properties. The self-assembly of bio-inspired building blocks enables comparison with proteins and their complex functionalities, providing preliminary insights into complex biological functions and also enabling their application in a wide range of fields.

[Frontispiece]
Nishant Singh, Mohit Kumar, Juan F. Miravet, Rein V. Ulijn, Beatriu Escuder
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201780561. Read article

Alcohol-Enhanced Cu-Mediated Radiofluorination

25 gennaio, 2017 - 00:00

Alcohol‐Enhanced Cu‐Mediated Radiofluorination

Alcohol is the solution: The potential of many 18F-labeled (hetero)aromatics for positron emission tomography (PET) remains underexploited, so the development and optimization of radiolabeling procedures remains a research area of considerable interest. It is shown herein that alcohol-containing solvent systems give rise to unexpectedly enhanced copper-mediated aromatic 18F-labeling, enabling rapid radiolabeling of a broad scope of boronic and stannyl substrates under general reaction conditions. Among others, this allows the direct synthesis of radiofluorinated indoles, phenols, and anilines from unprotected precursors. More information can be found in the Communication by B. Neumaier et al. (DOI: 10.1002/chem.201604633).

[Cover Picture]
Johannes Zischler, Niklas Kolks, Daniel Modemann, Bernd Neumaier, Boris D. Zlatopolskiy
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201700191. Read article

Robust Colloidal Nanoparticles of Pyrrolopyrrole Cyanine J-Aggregates with Bright Near-Infrared Fluorescence in Aqueous Media: From Spectral Tailoring to Bioimaging Applications

25 gennaio, 2017 - 00:00

 From Spectral Tailoring to Bioimaging Applications

Near-infrared fluorescent J-aggregates were discovered in colloidal nanoparticles of pyrrolopyrrole cyanines stabilized by amphiphilic block co-polymers in aqueous media. The formation of such colloidal-state J-aggregates can be tuned by the chemical structure and the concentration of the chromophores inside the polymeric nanoparticles, and can be further enhanced by ultrasonic treatment. These J-aggregate nanoparticles with an average diameter of 30 nm, exhibit a narrow emission band at 773 nm, a fluorescence quantum yield comparable to that of indocyanine green, and significantly enhanced photostability that is ideal for long-term bioimaging. More information can be found in the Full Paper by M. Wang et al. on page ▪▪ ff. (DOI: 10.1002/chem.201604741).

[Cover Picture]
Cangjie Yang, Xiaochen Wang, Mingfeng Wang, Keming Xu, Chenjie Xu
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201700125. Read article

Enantioselective Total Synthesis and Structure Confirmation of the Natural Dimeric Tetrahydroxanthenone Dicerandrol C

25 gennaio, 2017 - 00:00

Enantioselective Total Synthesis and Structure Confirmation of the Natural Dimeric Tetrahydroxanthenone Dicerandrol C

All natural: The first enantioselective total synthesis of a natural dicerandrol containing a dimeric tetrahydroxanthenone skeleton is described starting from an enantiopure chromane, which was obtained through a Wacker-type cyclization with >99 % ee. For the formation of the dimeric skeleton a palladium-catalyzed Suzuki reaction was used. The synthesis allowed an unambiguous proof of the absolute and relative configuration of the natural product.

[Communication]
Dhandapani Ganapathy, Johannes R. Reiner, Guillermo Valdomir, Soundararasu Senthilkumar, Lutz F. Tietze
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201700020. Read article

Double Reduction of 4,4′-Bipyridine and Reductive Coupling of Pyridine by Two Thorium(III) Single-Electron Transfers

25 gennaio, 2017 - 00:00

Double Reduction of 4,4′‐Bipyridine and Reductive Coupling of Pyridine by Two Thorium(III) Single‐Electron Transfers

The Mighty Thorium: The reductive chemistry of the thorium(III) complex, [Th{C5H3(SiMe3)2-1,3}3], is shown to be of the order of non-traditional lanthanide(II) complexes, opening up new reductive chemistry for the actinides.

[Communication]
Alasdair Formanuik, Fabrizio Ortu, Jingjing Liu, Lydia E. Nodaraki, Floriana Tuna, Andrew Kerridge, David P. Mills
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201605974. Read article

Step-Edge Assisted Direct Linear Alkane Coupling

25 gennaio, 2017 - 00:00

Step‐Edge Assisted Direct Linear Alkane Coupling

Direct coupling of alkanes via C−H activation of terminal methyl groups has been achieved at the step edges of Cu surfaces at modulated temperatures. The mechanism of the reaction has been elucidated and demonstrated that the low activation barrier relies on heterogeneous catalysis at the upper step edges, where low-coordinated surface atoms are present.

[Full Paper]
Junjie Zhang, Chun-ran Chang, Biao Yang, Nan Cao, Chencheng Peng, Haiming Zhang, Dan-Tam D. Tang, Frank Glorius, Gerhard Erker, Harald Fuchs, Qing Li, Lifeng Chi
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201605744. Read article

Nacnac-Cobalt-Mediated P<sub>4</sub> Transformations

25 gennaio, 2017 - 00:00

Nacnac‐Cobalt‐Mediated P4 Transformations

Different [LCo]-mediated (L=nacnac) P4 transformations are presented. The Co0 source leads to a mixture of mono-anionic complexes containing cyclo-P4 and cyclo-P3 middle decks. In contrast, the corresponding CoI starting material transforms selectively P4 into the neutral cyclo-P4 compound. Under thermal conditions, one P atom is extruded and a neutral compound with cyclo-P3 ligand is formed. Alternatively, the pro-ducts are selectively obtained by the reduction of their neutral relatives.

[Full Paper]
Fabian Spitzer, Christian Graßl, Gábor Balázs, Eric Mädl, Martin Keilwerth, Eva M. Zolnhofer, Karsten Meyer, Manfred Scheer
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201605451. Read article

Access to Enantiopure Triarylmethanes and 1,1-Diarylalkanes by NHC-Catalyzed Acylative Desymmetrization

25 gennaio, 2017 - 00:00

Access to Enantiopure Triarylmethanes and 1,1‐Diarylalkanes by NHC‐Catalyzed Acylative Desymmetrization

Three′s the charm: We present herein a general, efficient and enantioselective synthesis of triarylmethanes and 1,1-diarylalkanes through N-heterocyclic carbene-catalyzed acylative desymmetrization of bisphenols. This method utilizes readily available substrates, reagents and a simple procedure to deliver the valuable products in excellent enantiopurity. DFT calculations provided a transition-state model featuring a combination of intramolecular hydrogen bond and steric effect to explain the enantioselectivity.

[Communication]
Shenci Lu, Xiaoxiao Song, Si Bei Poh, Hui Yang, Ming Wah Wong, Yu Zhao
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201605445. Read article

Sustainable Synthesis of Balsalazide and Sulfasalazine Based on Diazotization with Low Concentrations of Nitrogen Dioxide in Air

25 gennaio, 2017 - 00:00

Sustainable Synthesis of Balsalazide and Sulfasalazine Based on Diazotization with Low Concentrations of Nitrogen Dioxide in Air

Out of thin air! The removal of nitrogen dioxide from gas streams was found to be highly effective when combined with the diazotization of polar anilines. In this way, the preparation of copper(II) nitrate can be coupled to a sustainable synthesis of industrially important azo compounds such as the pharmaceuticals balsalazide and sulfasalazine.

[Communication]
Dagmar Hofmann, Eva Gans, Jasmin Krüll, Markus R. Heinrich
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201605359. Read article

A Bio-Chemosynthetic Approach to Superparamagnetic Iron Oxide–Ansamitocin Conjugates for Use in Magnetic Drug Targeting

25 gennaio, 2017 - 00:00

A Bio‐Chemosynthetic Approach to Superparamagnetic Iron Oxide–Ansamitocin Conjugates for Use in Magnetic Drug Targeting

Hot and toxic! The combination of muta- and semisynthesis yields a modified toxic ansamitocin, which was loaded to functionalized superparamagnetic, nanostructured particles. The toxin (IC50 in the lower nanomolar range) was released in an external electromagnetic field through inductive heating. The conjugate concept allows the combination of hyperthermia with chemotherapy in anticancer research.

[Communication]
Liang-Liang Wang, Asha Balakrishnan, Nadja-Carola Bigall, David Candito, Jan Frederick Miethe, Katja Seidel, Yu Xie, Michael Ott, Andreas Kirschning
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201604903. Read article

Progress in Enantioselective Radical Cyclizations

25 gennaio, 2017 - 00:00

Progress in Enantioselective Radical Cyclizations

Remarkable progress in enantioselective radical cyclization reactions has taken place recently. This Review summarizes radical cyclizations controlled by chiral Lewis acids, chiral metallic reagents, chiral imidazolidinone catalysts, chiral non-covalent organocatalysts, and chiral thiols.

[Review]
Hideto Miyabe, Akira Kawashima, Eito Yoshioka, Shigeru Kohtani
Chem. Eur. J., January 25, 2017, DOI: 10.1002/chem.201603124. Read article

Versatile Interacting Peptide (VIP) Tags for Labeling Proteins with Bright Chemical Reporters

25 gennaio, 2017 - 00:00

Versatile Interacting Peptide (VIP) Tags for Labeling Proteins with Bright Chemical Reporters

VIPs only: New methods that facilitate attachment of photostable synthetic fluorophores with genetic specificity are needed for advancements in biological imaging. We describe a new set of small, selective, genetically encoded versatile interacting peptide (VIP) tags based on a heterodimeric coiled-coil interaction between two peptides, CoilY and CoilZ.

[Communication]
Hannah K. Zane, Julia K. Doh, Caroline A. Enns, Kimberly E. Beatty
ChemBioChem, January 25, 2017, DOI: 10.1002/cbic.201600627. Read article

Optical Control of DNA Helicase Function through Genetic Code Expansion

25 gennaio, 2017 - 00:00

Optical Control of DNA Helicase Function through Genetic Code Expansion

Expanding the helix: By using genetic code expansion, an optical switch was engineered into the DNA helicase UvrD. A hydroxycoumarin-caged lysine (HCK) was inserted into the active site of the UvrD ATPase domain, thus rendering the enzyme inactive until irradiation removes the caging group and generates an active (wild-type) helicase.

[Communication]
Ji Luo, Muwen Kong, Lili Liu, Subhas Samanta, Bennett Van Houten, Alexander Deiters
ChemBioChem, January 25, 2017, DOI: 10.1002/cbic.201600624. Read article

Kemp Elimination Catalyzed by Naturally Occurring Aldoxime Dehydratases

25 gennaio, 2017 - 00:00

Kemp Elimination Catalyzed by Naturally Occurring Aldoxime Dehydratases

N-O means N-O, does it? Natural aldoxime dehydratases can break 1,2-benzisoxazoles by catalyzing the non-natural Kemp elimination reaction. Mutational studies and control of the iron(II) heme redox state suggest a strong structure–activity relationship for the C=N-O motif.

[Communication]
Yufeng Miao, Richard Metzner, Yasuhisa Asano
ChemBioChem, January 25, 2017, DOI: 10.1002/cbic.201600596. Read article

Achievements, Challenges, and Opportunities in DNA-Encoded Library Research: An Academic Point of View

25 gennaio, 2017 - 00:00

 An Academic Point of View

Discovery with DECLs: Encoding with DNA sequence barcodes enables rapid and inexpensive synthesis and interrogation of compound libraries of unprecedented size. Screening DNA-encoded chemical libraries (DECLs) is increasingly used in drug discovery, with applications in chemical biology under development. This minireview summarizes key achievements in the field and analyzes its challenges and opportunities.

[Minireview]
Lik Hang Yuen, Raphael M. Franzini
ChemBioChem, January 25, 2017, DOI: 10.1002/cbic.201600567. Read article

The Synthesis of 3-Arylquinolines from <i>o</i>-Nitrobenzaldehydes and <i>β</i>-Nitrostyrenes via an Iron-Promoted Reductive Cyclization

24 gennaio, 2017 - 00:00

The Synthesis of 3‐Arylquinolines from o‐Nitrobenzaldehydes and &#x3B2;‐Nitrostyrenes via an Iron‐Promoted Reductive Cyclization

A novel and efficient protocol for the synthesis of 3-arylquinolines from o-nitrobenzaldehydes and &#x3B2;-nitrostyrenes promoted by iron has been developed. Iron acted as a double-reducing reagent to trigger the reduction of o-nitrobenzaldehydes and reduction hydrolysis of &#x3B2;-nitrostyrenes to generate phenylaldehydes and o-aminobenzaldehydes, which subsequently integrated to quinoline derivatives.

[Communication]
Deng-Kui Li, Qun Cai, Rong-Rong Zhou, Yan-Dong Wu, An-Xin Wu
ChemistrySelect, January 24, 2017, DOI: 10.1002/slct.201700063. Read article

Cover Picture: Mass Spectrometric Coverage of Complex Mixtures: Exploring the Carbon Space of Crude Oil (ChemistrySelect 03/2017)

24 gennaio, 2017 - 00:00

 Exploring the Carbon Space of Crude Oil (ChemistrySelect 03/2017)

The cover picture illustrates that the analysis of crude oils resembles a journey into an unknown space – the carbon space. Compounds are made up of aromatic rings with aliphatic sidechains, all mixed up together with occasional heteroatoms splattered in, resulting in a vast array of different structures and chemical formulas, exceeding more than one million distinct compounds. In the single droplets some core structures are shown as examples. The central feature of the picture shows, how this variety of compounds can be addressed by ultrahigh resolving mass spectrometry starting with the sample drop, through ionization, spectra recording to data calculation and interpretation. The very crowded mass spectra require different approaches of data interpretation were the diagram shows one possible representation of all compounds, based on the amount of heteroatoms per molecule. More information can be found in the Communication by Schrader et al. (DOI: 10.1002/slct.201601083).

[Cover Picture]
Alessandro Vetere, Wolfgang Schrader
ChemistrySelect, January 24, 2017, DOI: 10.1002/slct.201700016. Read article

Absorption competition quenching mechanism of porous covalent organic polymer as luminescent sensor for selective sensing Fe<sup>3+</sup>

24 gennaio, 2017 - 00:00

Absorption competition quenching mechanism of porous covalent organic polymer as luminescent sensor for selective sensing Fe3+

We synthesized three luminescent covalent-organic polymers (COPs) by Ni-catalyzed Yamamoto reaction, and they can be used as luminescent probe for sensing Fe3+. Meanwhile, we revealed the absorption competition quenching (ACQ) mechanism of the COPs for sensing Fe3+, and it is expected that the ACQ mechanism provided here can be used as an efficient strategy to design the new luminescent sensors for applications of interest.

[Full Paper]
Lin Guo, Xiaofei Zeng, Jianhui Lan, Jimmy Yun, Dapeng Cao
ChemistrySelect, January 24, 2017, DOI: 10.1002/slct.201602076. Read article

Intermolecular Stetter Reactions on Morita-Baylis-Hillman Adducts: an Approach to Highly Functionalized 1,4-Dicarbonyl Compounds

24 gennaio, 2017 - 00:00

 an Approach to Highly Functionalized 1,4‐Dicarbonyl Compounds

We reported an efficient method to prepare 1,4-dicarbonyl compounds combining the Morita-Baylis-Hillman adducts and Stetter reaction. This metal-free process exhibits a wide substrate scope, excellent atom economy, compatibility with functionalized substrates and mild reaction conditions.

[Full Paper]
Ralph C. Gomes, Rosimeire C. Barcelos, Manoel T. Rodrigues, Hugo Santos, Fernando Coelho
ChemistrySelect, January 24, 2017, DOI: 10.1002/slct.201602059. Read article

Copyright © 2012 Società Chimica Italiana. All Rights Reserved.