• Issue

    Angewandte Chemie International Edition: Volume 55, Issue 46

    14179-14468
    November 7, 2016

Cover Pictures

Free Access

Cover Picture: Deactivation of Mcl-1 by Dual-Function Small-Molecule Inhibitors Targeting the Bcl-2 Homology 3 Domain and Facilitating Mcl-1 Ubiquitination (Angew. Chem. Int. Ed. 46/2016)

  • Pages: 14179
  • First Published: 18 October 2016
Description unavailable

Promotion of Mcl-1 protein binding to the ubiquitin ligase Mule to catalyze its ubiquitination could enhance an apoptotic signaling pathway in cancer cells. In their Communication on page 14250 ff. Z. Zhang and co-workers identify a compound that zips these two proteins together by driving a non-helical QRN motif on Mc1-1 to adopt a helical conformation.

Free Access

Inside Cover: Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands (Angew. Chem. Int. Ed. 46/2016)

  • Pages: 14180
  • First Published: 21 September 2016
Description unavailable

Cobalt complexes bearing an anionic PNP-type pincer ligand are effective catalysts for the reduction of molecular dinitrogen into ammonia under mild reaction conditions, as shown by K. Yoshizawa, Y. Nishibayashi, and co-workers in their Communication on page 14291 ff. These findings provide valuable insight for the development of nitrogen fixation systems based on transition-metal dinitrogen complexes as catalysts.

Free Access

Inside Back Cover: tRNA Shifts the G-quadruplex–Hairpin Conformational Equilibrium in RNA towards the Hairpin Conformer (Angew. Chem. Int. Ed. 46/2016)

  • Pages: 14469
  • First Published: 20 September 2016
Description unavailable

Transfer RNA (tRNA) transforms mRNA conformation. In their Communication on page 14315, N. Sugimoto and co-workers demonstrate a shift in the conformation of oncogenic mRNAs, from G-quadruplex (G4) to hairpin conformation, caused by tRNA. tRNA is one of the cellular abundant non-coding RNAs and is overexpressed in cancer cells. The reduction of G4-mediated translation suppression as a result of the mRNA conformational change suggests a novel function of tRNA in the regulation of oncogene expression.

Free Access

Back Cover: Few-Layer Antimonene by Liquid-Phase Exfoliation (Angew. Chem. Int. Ed. 46/2016)

  • Pages: 14470
  • First Published: 11 October 2016
Description unavailable

Sonication-assisted liquid-phase exfoliation of antimony crystals gives rise to very stable suspensions of high-quality single/few-layer antimonene, as shown by G. Abellán, F. Zamora, and co-workers in their Communication on page 14345 ff. A new nanomaterial was thus produced that will facilitate the development of a broad range of applications based on antimonene, including electronics and optoelectronics.

Frontispiece

Free Access

Frontispiece: Bilayer Networks within a Hydrogel Shell: A Robust Chassis for Artificial Cells and a Platform for Membrane Studies

  • First Published: 03 November 2016
Description unavailable

Lipid Bilayers In their Communication on page 14240 ff., O. K. Castell et al. report droplet networks that are separated by lipid membranes and encapsulated within a semipermeable shell.

Graphical Abstract

Free Access

Graphical Abstract: Angew. Chem. Int. Ed. 46/2016

  • Pages: 14183-14196
  • First Published: 03 November 2016

Author Profiles

Free Access

Jun Chen

  • Pages: 14204
  • First Published: 08 June 2016
Description unavailable

“The most important thing I learned from my parents is diligence. My favorite food is steamed fish ...” This and more about Jun Chen can be found on page 14204.

Highlights

Organocatalysis

The First Organocatalytic Cope Rearrangement

  • Pages: 14208-14209
  • First Published: 22 September 2016
Description unavailable

Exploiting the concept of iminium ion catalysis led to the discovery of the first organocatalytic Cope rearrangement of 1,5-hexadiene-2-carboxaldehydes. A diazepane catalyst exhibited optimal catalytic efficiency and offers possibilities for chiral modification.

Minireviews

Gold Catalysis

Industrial Applications of Gold Catalysis

  • Pages: 14210-14217
  • First Published: 14 September 2016
Description unavailable

Golden future: Gold catalysis has recently found large-scale applications in industry. This Minireview analyzes the success factors and main obstacles that had to be overcome on the long way from the discovery of gold catalysts to commercialization. The picture shows a carbide-based PVC plant in China for the gold-catalyzed hydrochlorination of acetylene. (We thank the United Nations Environment Programme and its Global Mercury Partnership for providing the picture.)

Reviews

Medicinal Chemistry

Accessing Drug Metabolites via Transition-Metal Catalyzed C−H Oxidation: The Liver as Synthetic Inspiration

  • Pages: 14218-14238
  • First Published: 10 October 2016
Description unavailable

Organic synthesis: This Review addresses an important question of great practical significance in the pharmaceutical industry: can classical and modern chemical C−H oxidation reactions complement biotransformation in the synthesis of drug metabolites? Drug metabolites are required throughout all phases of the drug discovery and development process; however, their synthesis is still an unsolved problem.

Communications

Lipid Bilayers

Open Access

Bilayer Networks within a Hydrogel Shell: A Robust Chassis for Artificial Cells and a Platform for Membrane Studies

  • Pages: 14240-14245
  • First Published: 11 October 2016
Description unavailable

Encapsulated droplet networks: Droplet networks separated by lipid membranes are encapsulated within a semi-permeable shell. These cell-like materials can spatially segregate defined compartments and communicate with the outside world using reconstituted membrane proteins. Such microfluidically prepared membrane constructs are stable in a range of environments.

Cisplatin | Very Important Paper

Base-Resolution Analysis of Cisplatin–DNA Adducts at the Genome Scale

  • Pages: 14246-14249
  • First Published: 13 October 2016
Description unavailable

Touching base: As a potent anticancer drug, cisplatin crosslinks DNA and ultimately triggers cell death. Cisplatin-seq is a new approach to decode cisplatin-modified DNA sites in the human genome with base resolution.

Inhibitors | Very Important Paper

Deactivation of Mcl-1 by Dual-Function Small-Molecule Inhibitors Targeting the Bcl-2 Homology 3 Domain and Facilitating Mcl-1 Ubiquitination

  • Pages: 14250-14256
  • First Published: 04 October 2016
Description unavailable

Switched: By using NMR methods and structure–activity relationship studies it was shown that a small-molecule inhibitor could induce the flexible QRN motif to form a helical conformation through interaction with His224, by which it facilitates Mcl-1 ubiquitination in living cells. The inhibitor demonstrates that Mcl-1 ubiquitination can be chemically exploited to effectively facilitate its deactivation, thus identifying an avenue for pharmacological intervention in Mcl-1 signaling.

Organocatalysis

γ′-Selective Functionalization of Cyclic Enones: Construction of a Chiral Quaternary Carbon Center by [4+2] Cycloaddition/Retro-Mannich Reaction with 3-Substituted Maleimides

  • Pages: 14257-14261
  • First Published: 13 October 2016
Description unavailable

Follow the path: The asymmetric title reaction leads to the construction of chiral quarternary carbon centers with excellent diastereoselectivity. An unprecedented isomerization takes place with 2-cyclopentenone and thus provides a pathway for easily building a new C−C bond at the β-site of 2-cyclopentenone with excellent enantioselectivity.

CO2 Reduction

Tunable Syngas Production from CO2 and H2O in an Aqueous Photoelectrochemical Cell

  • Pages: 14262-14266
  • First Published: 14 October 2016
Description unavailable

Mixture is better: Syngas (CO+H2) with tunable composition is synthesized from the reduction of CO2 and H2O in an aqueous photoelectrochemcal cell. A turnover number of 1330 and a high Faradaic efficiency of 70 % for CO at underpotential of 180 mV are acheived. The excellent perfomance is attributed to the coupling effects of strong light harvesting of p-n Si, efficient electron extraction of GaN nanowires, and fast surface reaction kinetics of Cu–ZnO co-catalysts.

Molecular Electronics

Length-Independent Charge Transport in Chimeric Molecular Wires

  • Pages: 14267-14271
  • First Published: 07 October 2016
Description unavailable

It's down to the wire: Charge transport in self-assembled monolayers from DNA-inspired, perylenediimide-based molecular wires was investigated electrochemically. The electron transfer rate for the chimeric wires was determined to be essentially independent of their length. These findings may afford new opportunities for the development of advanced molecular electronic components.

Photochemistry

Tailoring Transition-Metal Hydroxides and Oxides by Photon-Induced Reactions

  • Pages: 14272-14276
  • First Published: 18 October 2016
Description unavailable

Photon-induced chemical reactions: Two reaction pathways, namely, photon-induced redox reactions under 532 nm laser-light irradiation and hydrolysis under 1064 nm laser-light irradiation, are comparatively studied. Distinct transition-metal hydroxide and oxide nanostructures are controllably fabricated by irradiating the aqueous precursor solutions with laser light.

Biocatalysis

Directed Evolution of a Fluorinase for Improved Fluorination Efficiency with a Non-native Substrate

  • Pages: 14277-14280
  • First Published: 14 October 2016
Description unavailable

Faster Fluorination: Fluorinases are challenging to engineer owing to high substrate specificity. A fluorinase (structure shown) was engineered through directed evolution and the evolved variants showed improved activity with the non-native substrate 5′-chloro-5′-deoxyadenosine. Kinetics studies revealed a faster first step of the reaction. Structural data suggest that the mutations lead to tighter binding of S-adenosyl-l-methionine.

Polymorphic Materials | Hot Paper

Mechanochemically Induced Conversion of Crystalline Benzamide Polymorphs by Seeding

  • Pages: 14281-14285
  • First Published: 20 October 2016
Description unavailable

Shapeshifter: Complete transformation of benzamide polymorph form I into the metastable form III by mechanochemical treatment is presented. Catalytic amounts of nicotinamide seeds activate conversion by mechanochemical seeding.

C−C Activation

Catalyst-Free Formal Thioboration to Synthesize Borylated Benzothiophenes and Dihydrothiophenes

  • Pages: 14286-14290
  • First Published: 13 October 2016
Description unavailable

Borylative cyclizations: The first ring-forming thioboration reaction of C−C π bonds is reported. The resulting borylated benzothiophenes participate in a variety of in situ derivatization reactions, showcasing that these borylated intermediates do not need to be isolated prior to downstream functionalization. Mechanistic experiments suggest a boron-induced activation of the alkyne followed by electrophilic cyclization.

Nitrogen Fixation | Hot Paper

Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands

  • Pages: 14291-14295
  • First Published: 16 August 2016
Description unavailable

Cobalt dinitrogen complexes with an anionic PNP-type pincer ligand enable the direct formation of ammonia from molecular dinitrogen under mild reaction conditions. Up to 15.9 equivalents of ammonia were produced based on the amount of catalyst together with one equivalent of hydrazine (17.9 equivalents of fixed N atoms).

Plasmonic Nanoparticles

Dry Sintering Meets Wet Silver-Ion “Soldering”: Charge-Transfer Plasmon Engineering of Solution-Assembled Gold Nanodimers From Visible to Near-Infrared I and II Regions

  • Pages: 14296-14300
  • First Published: 12 October 2016
Description unavailable

Metamorphosis in silica cocoon: An Ag+ soldered, Au nanoparticle (NP) dimer is embedded in a SiO2 nanoreactor and sintered at elevated temperatures. The resulting structures exhibit a widely tunable charge-transfer plasmon (CTP) spanning an 800 nm wavelength range. The degree of shape transformation of the NP dimer on sintering tunes the localized surface plasmon resonance (LSPR) shift from visible to the NIR I, II domains.

Nonequilibrium Processes

Retrograde and Direct Wave Locomotion in a Photosensitive Self-Oscillating Gel

  • Pages: 14301-14305
  • First Published: 13 October 2016
Description unavailable

Come on baby, do the locomotion: A model for biological crawling locomotion that exhibits retrograde (earthworm) and direct (snail) locomotion is presented. BZ waves and stimulus-reponsive gels were employed as analogues of nerve pulses and deformable muscles, respectively. Simulations show that spatially non-uniform illumination modulates the asymmetry of pulse waves, resulting in transitions between retrograde and direct wave locomotion of the BZ gel.

Total Synthesis

Open Access

A Cascade Strategy Enables a Total Synthesis of (±)-Morphine

  • Pages: 14306-14309
  • First Published: 13 October 2016
Description unavailable

A classical target: A novel total synthesis of (±)-morphine employs two key strategic cyclizations: 1) a diastereoselective light-mediated cyclization of an O-arylated butyrolactone to form a tricyclic cis-fused benzofuran and 2) a cascade ene–yne–ene ring closing metathesis to forge the tetracyclic morphine core. This stereoselective approach affords morphine in an overall yield of 6.6 %.

Single-Atom Catalysts

Efficient Visible-Light-Driven Carbon Dioxide Reduction by a Single-Atom Implanted Metal–Organic Framework

  • Pages: 14310-14314
  • First Published: 13 October 2016
Description unavailable

Less is more: A photocatalyst comprising atomically dispersed Co in an extended MOF efficiently reduces CO2. Directional migration of photogenerated excitons from porphyrin to catalytic cobalt centers was witnessed, thereby supplying long-lived electrons for reduction of CO2 molecules adsorbed on cobalt centers.

Regulatory RNAs

tRNA Shifts the G-quadruplex–Hairpin Conformational Equilibrium in RNA towards the Hairpin Conformer

  • Pages: 14315-14319
  • First Published: 11 August 2016
Description unavailable

Making hairpins: In clinically important mRNAs, an equilibrium between G-quadruplex and hairpin structures appears to regulate biological processes. Non-coding tRNAs are shown to significantly shift the equilibrium towards the hairpin conformer. The results suggest that the tRNAs might serve as therapeutic targets.

Perovskite Crystal Structure

Short-Range Order of Methylammonium and Persistence of Distortion at the Local Scale in MAPbBr3 Hybrid Perovskite

  • Pages: 14320-14324
  • First Published: 13 October 2016
Description unavailable

Keep it local: The short-range order of the methylammonium (MA) group in MAPbBr3 perovskite was investigated by neutron scattering as a function of temperature and by pair distribution function analysis. The results strongly support a situation where the MA group maintains a nearly constant local arrangement and connection with the Br cage irrespective of the long-range structure of the crystal phases (orthorhombic, tetragonal, cubic).

Uranium Cluster

Isolation of a Star-Shaped Uranium(V/VI) Cluster from the Anaerobic Photochemical Reduction of Uranyl(VI)

  • Pages: 14325-14329
  • First Published: 14 October 2016
Description unavailable

Assembling with light: Photolysis of uranyl(VI) benzoate in the presence of water leads to the reduction of uranyl(VI), and to the incorporation of the resulting UV into the stable star-shaped mixed-valent UVI/UV oxo cluster [U(UO2)5-(μ3-O)5(PhCOO)5(Py)7].

Anti-Inflammatory Compounds

Exploring the Binding Proteins of Glycolipids with Bifunctional Chemical Probes

  • Pages: 14330-14334
  • First Published: 20 October 2016
Description unavailable

Search and find: A bifunctional probe design based on monogalactosyldiacylglycerol (MGDG) for mechanistic studies of glycolipids in living system was developed. A typical MGDG probe enabled the identification of TLR4 as its cellular target. In combination with biochemical studies and molecular modeling, it was demonstrated that binding of MGDG to TLR4/MD-2 leads to its anti-inflammatory activity.

Frustrated Lewis Pairs

A Frustrated and Confused Lewis Pair

  • Pages: 14335-14339
  • First Published: 13 October 2016
Description unavailable

A confused isomer: A new class of frustrated Lewis pairs (FLPs) resulted from hydroboration of isocyanates, which provided N-formyl aminoboranes (see picture). This “confused” isomer showed the typical behavior of a frustrated Lewis pair, such as capture of unsaturated substrates, through interconversion with its frustrated form.

Medium-Sized Rings

A Migratory Ether Formation Route to Medium-Sized Sugar Mimetics

  • Pages: 14340-14344
  • First Published: 13 October 2016
Description unavailable

Biomolecular building blocks: In a general route to medium-sized polyol cyclic ethers, Me3Al promotes an unprecedented intramolecular epoxide-opening by an ether addition reaction. The resulting oxonium intermediate triggers a 1,3-methyl shift to yield 2-deoxyribital products. When the hemiacetal auxiliary is a monosaccharide, the sugar ring is expanded by four atoms to give the 9- to 11-membered analogues.

Two-Dimensional Materials | Hot Paper

Open Access

Few-Layer Antimonene by Liquid-Phase Exfoliation

  • Pages: 14345-14349
  • First Published: 16 August 2016
Description unavailable

Very stable suspensions of high-quality single- or few-layer antimonene were obtained by liquid-phase exfoliation under sonication without the need for a surfactant. The Raman spectrum of antimonene was found to strongly depend on its thickness, which was also rationalized by quantum-mechanical calculations.

Azide Complexes

The Binary Group 4 Azides [PPh4]2[Zr(N3)6] and [PPh4]2[Hf(N3)6]

  • Pages: 14350-14354
  • First Published: 13 October 2016
Description unavailable

Nothing but N: Binary zirconium and hafnium polyazides [PPh4]2[M(N3)6] (M=Zr, Hf) were prepared from the corresponding metal fluorides MF4 and two equivalents of [PPh4][N3] by fluoride–azide exchange with Me3SiN3. Both novel azido salts were characterized by X-ray crystal structure analysis, vibrational and NMR spectra, and decomposition temperatures.

Reactive Intermediates

Reversible Silylene Insertion Reactions into Si−H and P−H σ-Bonds at Room Temperature

  • Pages: 14355-14358
  • First Published: 18 October 2016
Description unavailable

New inserts: Phosphine-stabilized silylenes react with silanes (or phosphine) by silylene insertion into E−H σ-bonds (E=Si,P) at room temperature to give the corresponding silanes. Of special interest, the process occurs reversibly at room temperature. These results demonstrate that both the oxidative addition and the reductive elimination processes can proceed at the silicon center under mild reaction conditions.

Total Synthesis

Concise, Enantioselective, and Versatile Synthesis of (−)-Englerin A Based on a Platinum-Catalyzed [4C+3C] Cycloaddition of Allenedienes

  • Pages: 14359-14363
  • First Published: 13 October 2016
Description unavailable

When the first is in, the rest will follow: A key step in the asymmetric synthesis of (−)-englerin A was a platinum-catalyzed [4C+3C] allenediene cycloaddition, which directly delivered the trans-fused bicyclic guaiane skeleton (see scheme). The seven stereocenters of the molecule were generated in a highly stereoselective fashion after initial ruthenium-catalyzed asymmetric transfer hydrogenation of the ketone cycloaddition precursor.

Green Chemistry

Highly Efficient Nitric Oxide Capture by Azole-Based Ionic Liquids through Multiple-Site Absorption

  • Pages: 14364-14368
  • First Published: 14 October 2016
Description unavailable

NO absorption: Using the reported method for highly efficient nitric oxide absorption, a NO absorption capacity of up to 4.52 mol per mol ionic liquid was reached. This capacity is significantly higher than the capacity of other traditional absorbents.

Synthetic Methods

Highly Selective Hydroboration of Alkenes, Ketones and Aldehydes Catalyzed by a Well-Defined Manganese Complex

  • Pages: 14369-14372
  • First Published: 14 October 2016
Description unavailable

Inexpensive and selective: Highly regioselective Markovnikov hydroboration of styrenes as well as excellent chemoselective hydroboration of ketones over alkenes were achieved by a well-defined manganese(II) alkyl catalyst based on a readily available ligand, 2,2′:6′,2′′-terpyridine. This represents the first example of an earth-abundant manganese-catalyzed hydroboration of alkenes, ketones and aldehydes.

Dehydrogenative Coupling | Hot Paper

Direct Synthesis of Pyrroles by Dehydrogenative Coupling of Diols and Amines Catalyzed by Cobalt Pincer Complexes

  • Pages: 14373-14377
  • First Published: 12 October 2016
Description unavailable

A complex of an earth-abundant metal is shown to catalyze the dehydrogenative coupling of diols and amines to form substituted pyrroles with liberation of H2 and water. Of the well-defined PNNH–Co pincer complexes tested in the presence of tBuOK and NaHBEt3, complex 1 turned out to be the most effective. The reaction is applicable to a wide range of primary alkyl amines, benzylic amines, and aromatic amines, and to primary and secondary diols.

Telechelic Polymers

Direct Synthesis of Telechelic Polyethylene by Selective Insertion Polymerization

  • Pages: 14378-14383
  • First Published: 13 October 2016
Description unavailable

Telechelic polyethylene: Using an insertion polymerization method, α,ω-di-furan telechelic PE was selectively synthesized in a single step. The method was extended to produce a novel hetero-functionalized PE with furan groups at α,ω-chain ends and anhydride group in the backbone. Combined experimental and DFT studies reveal the key for this direct approach to telechelics.

Lithium-Ion Batteries | Hot Paper

A Self-Healing Aqueous Lithium-Ion Battery

  • Pages: 14384-14388
  • First Published: 12 October 2016
Description unavailable

Battery, heal thyself: A new family of solid-state flexible aqueous lithium-ion batteries that can self-heal has been created using aligned carbon nanotube sheets loaded with LiMn2O4 and LiTi2(PO4)3 nanoparticles on a polymer substrate as electrodes and Li2SO4/carboxymethylcellulose as gel electrolyte and separator. The battery performance was well maintained after repeated cycles of cutting and self-healing.

Synthetic Methods

Trapping σ-Alkyl–Palladium(II) Intermediates with Arynes Encompassing Intramolecular C−H Activation: Spirobiaryls through Pd-Catalyzed Cascade Reactions

  • Pages: 14389-14393
  • First Published: 14 October 2016
Description unavailable

From simple to complex: A palladium-catalyzed cascade Heck carbopalladation/C−H activation/aryne insertion provides easy access to spirobiaryls. The process takes advantage of several aspects of Pd chemistry, i.e., intra- and intermolecular carbopalladation of unsaturated species, C−H activation, and C−C coupling processes.

Organocatalysis

Exploiting the Imidazolium Effect in Base-free Ammonium Enolate Generation: Synthetic and Mechanistic Studies

  • Pages: 14394-14399
  • First Published: 20 October 2016
Description unavailable

Drop the Base: N-Acyl imidazoles act as ammonium enolate precursors in the presence of catalytic isothiourea hydrochloride salts in the absence of base. Subsequent reactions with various Michael acceptors proceed with high stereoselectivity. Mechanistic investigations revealed the importance of the “imidazolium effect” during enolate formation and highlight key differences with traditional base-mediated processes.

Synthetic Methods

Synthesis of β-Boryl-α-Aminosilanes by Copper-Catalyzed Aminoboration of Vinylsilanes

  • Pages: 14400-14404
  • First Published: 18 October 2016
Description unavailable

Give me N and B: A copper-catalyzed regioselective and stereospecific aminoboration of vinylsilanes with bis(pinacolato)diboron and hydroxylamines proceeds to deliver the corresponding β-boryl-α-aminosilanes in good yields. The products can be readily transformed into highly functionalized α-aminosilanes of potent interest in medicinal chemistry. Additionally, with a chiral (R,R)-Ph-BPE ligand the reaction can be conducted in an enantioselective fashion.

Carbocycles

Highly Selective Construction of Seven-Membered Carbocycles by Olefin-Assisted Palladium-Catalyzed Oxidative Carbocyclization–Alkoxycarbonylation of Bisallenes

  • Pages: 14405-14408
  • First Published: 13 October 2016
Description unavailable

Medium-sized rings: An olefin-assisted palladium-catalyzed oxidative carbocyclization–alkoxycarbonylation of bisallenes was developed to afford seven-membered carbocycles. The reaction shows high chemo- and regioselectivity as ester 1 was the only product obtained. The ligand exchange of olefin with the second allene moiety was proposed as the key for the formation of the 7-membered ring.

Energetic Materials

Energetic N-Nitramino/N-Oxyl-Functionalized Pyrazoles with Versatile π–π Stacking: Structure–Property Relationships of High-Performance Energetic Materials

  • Pages: 14409-14411
  • First Published: 20 October 2016
Description unavailable

Explosives engineering: A family of new nitramino/oxyl-functionalized energetic pyrazoles was developed and studied. Their energetic properties indicated that π–π stacking is a key factor in determining the overall performance.

Energy Conversion

Platinum Alloy Tailored All-Weather Solar Cells for Energy Harvesting from Sun and Rain

  • Pages: 14412-14416
  • First Published: 14 October 2016
Description unavailable

I don't care what the weather man says: Tailored platinum alloy all-weather solar cells yield a photoelectric conversion efficiency of 10.38 % under simulated sunlight irradiation as well as a current of 3.90 μA and voltage of 115.52 μV under simulated raindrops. This work offers a strategy of developing advanced all-weather solar cells.

Asymmetric Catalysis

Open Access

Catalytic Asymmetric Allylboration of Indoles and Dihydroisoquinolines with Allylboronic Acids: Stereodivergent Synthesis of up to Three Contiguous Stereocenters

  • Pages: 14417-14421
  • First Published: 13 October 2016
Description unavailable

One, two, three: The catalytic asymmetric allylboration of cyclic imines with γ,γ-disubstituted allylboronic acids provides products with adjacent stereocenters in high yield and stereoselectivity. 3-Methylindole, for example, was converted into products with three adjacent stereocenters in one synthetic operation.

Anion–π Catalysis | Hot Paper

Asymmetric Anion–π Catalysis on Perylenediimides

  • Pages: 14422-14426
  • First Published: 14 October 2016
Description unavailable

Space, finally! The explicit investigation of perylenediimides for anion–π catalysis reveals a remarkably rich picture dominated by giant quadrupole moments, space to accommodate larger transformations, highest enantioselectivities so far, and decreasing activity with increasing twist.

Redox-Flow Batteries

An Aqueous Redox-Flow Battery with High Capacity and Power: The TEMPTMA/MV System

  • Pages: 14427-14430
  • First Published: 18 October 2016
Description unavailable

Tempting solutions: Redox-flow batteries (RFB) are widely considered as energy-storage solutions for wind generators and solar farms. A highly soluble, organic material system for aqueous RFBs is found to be N,N,N-2,2,6,6-heptamethyl piperidinyl oxy-4-ammonium chloride (TEMPTMA) and N,N′-dimethyl-4,4-bipyridinium dichloride (MV). It has capacities of over 54 Ah L−1 (ca. 38 Wh L−1), a cell voltage of 1.4 V, and peak current densities of up to 200 mA cm−2.

Glycosylation

Nucleophile-Directed Stereocontrol Over Glycosylations Using Geminal-Difluorinated Nucleophiles

  • Pages: 14431-14434
  • First Published: 13 October 2016
Description unavailable

Flirting with fluorine: Lowering the nucleophilicity of aliphatic amino alcohols by difluorination drastically increases the 1,2-cis-stereoselectivity in glycosylations to produce conjugation-ready glycans that are suitable for biological evaluation. Bn=benzyl, Cbz=benzyloxycarbonyl, LG=leaving group.

Sulfur Ylides

Sulfonium Ylides by (3+2) Cycloaddition of Arynes with Vinyl Sulfides: Stereoselective Synthesis of Highly Substituted Alkenes

  • Pages: 14435-14438
  • First Published: 13 October 2016
Description unavailable

A new approach to sulfur ylides: The (3+2) cycloaddition of arynes and vinyl sulfides represents a conceptually novel approach to the direct generation of sulfonium ylides, which further react to yield highly substituted alkenes with excellent stereoselectivity (see scheme).

Phosphanoxyl Complexes

Strong Evidence of a Phosphanoxyl Complex: Formation, Bonding, and Reactivity of Ligated Phosphorus Analogues of Nitroxides

  • Pages: 14439-14443
  • First Published: 13 October 2016
Description unavailable

Build up to break: P-OTEMP phosphane metal complex I preferentially undergoes homolytic O−N bond cleavage forming the transient phosphanoxyl complex II. DFT calculations provide insight into the formation of I as well as into the homolysis processes of I and the trapping reactions of II.

Cage Compounds

Alleno-Acetylenic Cage (AAC) Receptors: Chiroptical Switching and Enantioselective Complexation of trans-1,2-Dimethylcyclohexane in a Diaxial Conformation

  • Pages: 14444-14449
  • First Published: 14 October 2016
Description unavailable

Enantioselective complexation: Enantiopure alleno-acetylenic cages show solvent-dependent binary conformational switching with dramatic differences in the chiroptical properties of the open and closed form. Complete chiral resolution of (±)-trans-1,2-dimethylcyclohexane is observed in X-ray co-crystal structures of the cage form. Inclusion complexation occurs in a higher-energy diaxial conformation of the guest.

Boron Ligands

Phosphine-Stabilized Borylenes and Boryl Anions as Ligands? Redox Reactivity in Boron-Based Pincer Complexes

  • Pages: 14450-14454
  • First Published: 14 October 2016
Description unavailable

As a free molecule, a phosphine-stabilized borylene is unstable, but it was isolated as an electron-donating ligand in an iron complex. This complex exhibits a unique reactivity pattern, undergoing a reversible B−H reductive elimination concomitant with oxidation of the boron(I) center.

Biomass

Degradation and Crystallization of Cellulose in Hydrogen Chloride Vapor for High-Yield Isolation of Cellulose Nanocrystals

  • Pages: 14455-14458
  • First Published: 20 October 2016
Description unavailable

Vapor over the cracks: The adsorption of hydrogen chloride vapor on water-covered cellulose microfibrils results in rapid degradation and increased crystallinity without a change in fiber morphology. This process constitutes an example of supramolecular tuning of native biological materials directly in the solid state.

Zeolite Structures

Defect Models of As-Made High-Silica Zeolites: Clusters of Hydrogen-Bonds and Their Interaction with the Organic Structure-Directing Agents Determined from 1H Double and Triple Quantum NMR Spectroscopy

  • Pages: 14459-14463
  • First Published: 14 October 2016
Description unavailable

Cause and defect: Two or three silanol groups interact with negative charge centers (SiO) in as-made high-silica zeolites. These defects interact preferably with the charge center in organic structure-directing agents, and this interaction is suggested to be important in the formation of zeolites.

Borylenes

Generation of Dicoordinate Boron(I) Units by Fragmentation of a Tetra-Boron(I) Molecular Square

  • Pages: 14464-14468
  • First Published: 12 October 2016
Description unavailable

All square: Reduction of a carbene-borane adduct provides the tetra(cyanoborylene) species [(cAAC)B(CN)]4 with a 12-membered (BCN)4 ring. This species was found to reduce two equivalents of AgCN to yield [(cAAC)B(CN)3] and fragmented into two-coordinate boron(I) units upon reaction with an NHC.