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EXCLUSIVE: Tiny animal carcasses found in buried Antarctic lake

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E47 modulates hepatic glucocorticoid action

E47 modulates hepatic glucocorticoid actionE47 modulates hepatic glucocorticoid action, Published online: 18 January 2019; doi:10.1038/s41467-018-08196-5 Glucocorticoids (GCs) are widely used anti-inflammatory drugs; however, long-term treatment causes metabolic side effects. Here, the authors show that E47 is a modulator of glucocorticoid receptor activity for a subset of target genes in mouse liver, and that loss of E47 protects mice from hyperglycemia and hepatic steatosis in response to GCs.

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Combining LOPIT with differential ultracentrifugation for high-resolution spatial proteomics

Combining LOPIT with differential ultracentrifugation for high-resolution spatial proteomicsCombining LOPIT with differential ultracentrifugation for high-resolution spatial proteomics, Published online: 18 January 2019; doi:10.1038/s41467-018-08191-w Spatial proteomics allows studying cellular protein localisations at system-wide scale. Here, the authors show that combining the previously developed hyperLOPIT method with differential centrifugation yields protein localisation maps at suborganellar resolution while reducing analysis time and input material.

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Cross-lineage protection by human antibodies binding the influenza B hemagglutinin

Cross-lineage protection by human antibodies binding the influenza B hemagglutininCross-lineage protection by human antibodies binding the influenza B hemagglutinin, Published online: 18 January 2019; doi:10.1038/s41467-018-08165-y Immune recognition of Influenza B virus (IBV) is poorly understood. Here, Liu et al. use flow cytometry to characterize IBV-specific memory B cell responses following seasonal vaccination and show that elicited cross-reactive antibodies can protect against infection, providing a platform for vaccine design.

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Aberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogramming

Aberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogrammingAberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogramming, Published online: 18 January 2019; doi:10.1038/s41467-018-08245-z There are distinct hypermethylation patterns in gene promoters in hepatocellular carcinomas (HCCs). Here, the authors show that the enhancer of C/EBPβ is recurrently hypomethylated in human HCCs, recapitulating this in a transgenic murine model and linking aberrant enhancer hypomethylation to hepatocarcinogenesis.

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Lsd1 as a therapeutic target in Gfi1-activated medulloblastoma

Lsd1 as a therapeutic target in Gfi1-activated medulloblastomaLsd1 as a therapeutic target in Gfi1-activated medulloblastoma, Published online: 18 January 2019; doi:10.1038/s41467-018-08269-5 Medulloblastoma is one of the most prevalent malignant brain tumors in children and has very poor prognosis. In this study, the authors show, using a mouse model of medulloblastoma, that Gfi1 promotes tumor growth by recruiting Lsd1, that this interaction inhibits genes involved in neuronal differentiation, and that Lsd1 may be a therapeutic target in Gfi1-activated tumors.

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Dual-barcoded shotgun expression library sequencing for high-throughput characterization of functional traits in bacteria

Dual-barcoded shotgun expression library sequencing for high-throughput characterization of functional traits in bacteriaDual-barcoded shotgun expression library sequencing for high-throughput characterization of functional traits in bacteria, Published online: 18 January 2019; doi:10.1038/s41467-018-08177-8 Gain of function methods based on gene overexpression are not easily applied to high-throughput screening across different experimental conditions. Here, the authors present Dub-seq, which separates overexpression library characterization from functional screening and uses random DNA barcodes to increase the experimental throughput.

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A selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in rats

A selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in ratsA selective inhibitor of mitofusin 1-βIIPKC association improves heart failure outcome in rats, Published online: 18 January 2019; doi:10.1038/s41467-018-08276-6 Beta II protein kinase C (βIIPKC) activation contributes to heart failure. Here the authors show, in a rat model of myocardial infarction, that heart failure outcome can be improved by selectively inhibiting the interaction between βIIPKC and its downstream mitochondrial target Mitofusin-1, and that this strategy is superior to global βIIPKC inhibition.

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The effect of publishing peer review reports on referee behavior in five scholarly journals

The effect of publishing peer review reports on referee behavior in five scholarly journalsThe effect of publishing peer review reports on referee behavior in five scholarly journals, Published online: 18 January 2019; doi:10.1038/s41467-018-08250-2 To increase transparency in science, some scholarly journals have begun publishing peer review reports. Here, the authors show how this policy shift affects reviewer behavior by analyzing data from five journals piloting open peer review.

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Incidence and prevalence of vitreomacular traction with and without macular hole in Germany

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Dermatomyositis associated with omalizumab therapy for severe asthma: a case report

Omalizumab is a humanized monoclonal antibody widely used for treatment of persistent allergic asthma and antihistamine-refractory chronic urticaria. Immediate adverse events to omalizumab are well characteriz...

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Positive end-expiratory pressure titration with electrical impedance tomography and pressure–volume curve in severe acute respiratory distress syndrome

The study objective was to compare titration of positive end-expiratory pressure (PEEP) with electrical impedance tomography (EIT) and with ventilator-embedded pressure–volume loop in severe acute respiratory ...

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Di (2-ethylhexyl) phthalate induces cardiac disorders in BALB/c mice

AbstractBecause of the extensive use of phthalates for domestic, medical, and industrial applications, the evaluation of their toxic effects is of major concern to public health. The aim of the present study was to assess the propensity of di (2-ethylhexyl) phthalate (DEHP), one of the most used phthalates, to cause oxidative cardiac damage in mice. DEHP was administered intraperitoneally at doses of 5, 50, and 200 mg/kg body weight for 30 consecutive days in BALB/c mice. We assessed the effect of DEHP on cardiac injury using biochemical profile (such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatinine phosphokinase (CPK), total cholesterol (T-CHOL), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)), parameters related to myocardiac oxidative stress, such as malondialdehyde (MDA) level, protein carbonyl (PC) concentration, and DNA fragmentation. In addition, we eval…

Anthropogenic impacts in the Changbai Mountain region of NE China over the last 150 years: geochemical records of peat and altitude effects

AbstractGeochemical records from peatlands are important tools for the interpretation of environmental signals preserved in the peat and the understanding anthropogenic impacts on remote mountain regions. In this paper, six 210Pb-dated peat cores located at 500–1900 m above sea level (asl) in the Changbai Mountains were used to reconstruct the pollution history over the past 150 years in northeastern (NE) China. The cores physicochemical parameters and 10 key chemical elements were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Results from loss on ignition (LOI), total organic carbon (TOC), and lithogenic element (Ti, Fe, and Mn) analysis show that the peatlands (Ch, Yc1 and Jb) over 900 m asl are ombrotrophic and the lower altitude peatlands (Dng, Jc, and Ha) are minerotrophic. There is a decreasing trend of trace element distribution with the altitude, mainly due to the local source input. The content of the magnetic particles and trace elements (Cu,…

Characteristics and source apportionment of PM 2.5 in Jiaxing, China

AbstractHerein we investigated the morphology, chemical characteristics, and source apportionment of fine particulate matter (PM2.5) samples collected from five sites in Jiaxing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that soot aggregates and coal-fired fly ash were generally the most abundant components in the samples. All the samples were analyzed gravimetrically for mass concentrations and their various compositions were determined. Our results revealed that the PM2.5 concentrations in the samples were in the following order: winter > spring > autumn > summer. The PM2.5 concentrations in winter and spring were higher than those in autumn and summer, except for inorganic elements. Carbonaceous species and water-soluble inorganic ions were the most abundant components in the samples, accounting for 26.17–50.44% and 34.27–49.6%, respectively. The high secondary organic carbon/organic carbon ratio indicated that secondary organic p…

Unprecedented high percentage of food waste powder filler in poly lactic acid green composites: synthesis, characterization, and volatile profile

AbstractThe attractive qualities of plastics lead us, around the world, to an enormous need for plastic goods, which results in their unsustainable overconsumption. Bio-based products are the core concept of circular economy, yet this sector suffers from the high cost of their production. In practice, biopolymers, such as polylactic acid (PLA), are still limitedly used, due to their expensiveness and not outstanding technological properties. A circular and sustainable solution would be to use waste from the food industry as filler that contributes to reduce the cost of PLA-based materials, thereby encouraging their widespread use. At the same time, this would be a circular approach to wisely upgrade food waste and prevent pollution. Ceramic food waste powder fillers from egg shells and from mussel shells were compounded with PLA at 180 °C to obtain composites, which contain an unprecedented high amount of filler, equal to 140 over 100 parts of PLA. We analyzed volatile organic compoun…

Modification of the existing maximum residue levels for spirotetramat in various crops

AbstractIn accordance with Article 6 of Regulation (EC) No 396/2005, the competent national authority in Belgium prepared a request to modify the existing maximum residue levels (MRLs) for the active substance spirotetramat in Florence fennels and rhubarbs. Furthermore, in accordance with Article 6 of Regulation (EC) No 396/2005, the applicant Bayer SAS submitted a request to the competent national authority in Austria to modify the existing MRLs for spirotetramat in the group of other small fruits and berries, kiwi fruits and garlic. The data submitted in support to both requests were found to be sufficient to derive MRL proposals for all the crops under consideration. Adequate analytical methods are available to enforce the proposed MRLs. Based on the risk assessment results, EFSA concluded that the short‐term and long‐term intake of residues resulting from the use of spirotetramat according to the intended agricultural practices is unlikely to present a risk to consumer health.

fr…

E47 modulates hepatic glucocorticoid action

from A via a.sfakia on Inoreader https://go.nature.com/2FICnbW

Combining LOPIT with differential ultracentrifugation for high-resolution spatial proteomics

from A via a.sfakia on Inoreader https://go.nature.com/2FAA8YT

Aberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogramming

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Safety for the environment of vitamin D3 for salmonids

AbstractThe Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) of EFSA assessed the safety for the target species and the consumer of the use of a maximum total level of 1.5 mg vitamin D3/kg feed in fish nutrition (2017). The assessment was based on data that had been provided by the Norwegian Food Safety Authority (NFSA). Since the data set provided by the NFSA did not include any new information concerning the safety for the user and the environment, the 2017 opinion did not address the potential effects of the proposed increase in the maximum authorised levels of vitamin D3 on the safety for the user and the environment. The NFSA has submitted additional data and the European Commission has requested EFSA to deliver a new opinion on the safety for the environment of vitamin D3 as a nutritional additive for salmonids. Planktonic microalgae, inhabiting the sea, are a large group of photosynthetic organisms that contain both vitamin D3 and provitamin D3. …

Safety of cassia gum as a feed additive for cats and dogs based on a dossier submitted by Glycomer GmbH

AbstractThe additive cassia gum consists mainly of high‐molecular weight polysaccharides composed primarily of a linear chain of 1,4‐β‐d‐mannopyranose units with 1,6‐linked α‐d‐galactopyranose units. In 2014, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) delivered an opinion on the safety and efficacy of cassia gum in cats and dogs. The Panel concluded, based on positive findings observed in a bacterial reverse mutation test with a semi‐refined cassia gum (about 70 mg anthraquinones/kg) but not with purified semi‐refined cassia gum that meets the specification as a food additive (< 0.5 mg anthraquinones/kg), that only purified semi‐refined cassia gum that meets the specifications of cassia gum as a food additive can be considered safe for cats and dogs, at a maximum content of 1.5% cassia gum (15,000 mg/kg feed) in dry matter, corresponding to 1.32% (13,200 mg/kg feed) in a standardised complete feed with 12% water content. The conclusion was confir…

Rapid Progression of Low-Grade Cervical Dysplasia into Invasive Cancer during Natalizumab Treatment for Relapsing Remitting Multiple Sclerosis

A 25-year-old patient treated for relapsing remitting multiple sclerosis (RRMS) with natalizumab had a rapid progression of a low grade squamous intraepithelial lesion to a FIGO stage 1B1 squamous cell carcinoma of the uterine cervix within 2 years. She was treated with radical hysterectomy and pelvic lymphadenectomy and subsequently developed a vault recurrence within 2 years. The recurrence was treated with definitive synchronous chemo-radiotherapy and she has been disease free for 7 years. This case and existing evidence on increased risk of developing cervical dysplasia under natalizumab show that MS patients under immunosuppressive therapy require close annual cervical screening with immediate investigation of abnormal test results.
Case Rep Oncol 2019;12:59–62

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Microbial production of butyl butyrate, a flavor and fragrance compound

AbstractButyl butyrate (BB) has been widely used as a flavor and fragrance compound in the beverage, food, perfume, and cosmetic industries. Currently, BB is produced through two-step processes; butanol and butyrate are first produced and are used as precursors for the esterification reactions to yield BB in the next step. Recently, an alternative process to the current process has been developed by using microorganisms for the one-pot BB production. In the one-pot BB process, alcohol acyl transferases (AATs) and lipases play roles in the esterification of butanol together with their co-substrates butyryl-CoA and butyrate, respectively. In this paper, we review the characteristics of two enzymes including AAT and lipase in the esterification reaction. Also, we review the one-pot processes for BB production by employing the wild-type and engineered Clostridium species and the engineered Escherichia coli strains, with the combination of AATs and lipases.

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Enhanced lake-eutrophication model combined with a fish sub-model using a microcosm experiment

AbstractEutrophication models are effective tools for assessing aquatic environments. The lake ecosystem consists of at least three trophic levels: phytoplankton, zooplankton, and fish. However, only a few studies have included fish sub-models in existing eutrophication models. In addition, no specific value or range is available for certain parameters of the fish sub-model. In the present study, a lake microcosm experimental system was established to determine the range of fish sub-model parameters. A three-trophic-level eutrophication model was established by combining the fish sub-model and eutrophication model. The Bayesian Markov Chain Monte Carlo and genetic algorithm method was used to calibrate the parameters of the eutrophication model. The results show that the maximum relative errors were due to phosphate (5.31%), the minimum relative error was due to nitrate (1.94%), and the relative error of dissolved oxygen, ammonia N, zooplankton, and chlorophyll ranged from 3 to 4%. Co…

In situ resuspension rate monitoring method in the littoral zone with multi-ecotypes of a shallow wind-disturbed lake

AbstractSediment resuspension has been recognized as a crucial internal process in aquatic ecosystems. However, there is still a lack of reliable measuring methods due to the complex hydrodynamic conditions in large shallow eutrophic lakes. In this study, sequential sediment traps (SST) and instantaneous multiple point (IMP) methods were compared at 6 sites located in the littoral zone of Zhushan Bay in Lake Taihu. Results show that the average resuspension rates (RRs) estimated using the IMP method at sites 1 to 6 were 266.39, 272.79, 235.17, 254.95, 392.25, and 483.85 g·m−2d−1, respectively. While the RRs estimated using the SST method were 195.16, 236.99, 116.76, 156.23, 389.53, and 509.85 g·m−2d−1, respectively. In wind-disturbed areas, both methods were suitable for RR analysis in large and shallow eutrophic lakes and SST provides high-resolution temporal RR estimations. However, in the areas with cyanobacterial blooms and vegetation cover, the IMP method overestimated the RR. Th…

External Reversal of Chirality Transfer in Photoswitches

Which way to go? The monoterpene l‐menthone was incorporated into the backbone of a photochromic diarylethene. Chirality transfer upon photocyclization leads to preferred formation of one major stereoisomer. Complete reversal of the diastereomeric outcome was achieved by altering either the chemical environment or the irradiation wavelength, resulting in selective formation of the minor isomer.
AbstractThe transfer of stereoinformation is at the heart of asymmetric reactions. By incorporating the natural monoterpene l‐menthone into the backbone of a diarylethene, we achieved efficient chirality transfer upon photocyclization, resulting in the preferred formation of one major closed isomer in a diastereomeric ratio (d.r.) of 85:15. More significantly, we were able to completely reverse the diastereomeric outcome of the ring closure simply by altering the chemical environment or the irradiation conditions. As a result, we could selectively accumulate the less favored minor closed isomer,…

Photooxidase‐Mimicking Nanovesicles with Superior Photocatalytic Activity and Stability Based on Amphiphilic Amino Acid and Phthalocyanine Co‐Assembly

Multiple weak synergetic interactions enable the generation of photooxidase‐mimicking nanovesicles that contain an amphiphilic amino acid as a simplified protein host and phthalocyanine as a chlorophyll active site model. These vesicles catalyze the oxidation of dopamine into leucodopaminechrome under aerobic conditions.
AbstractEnzyme mimics have broad applications in catalysis and can assist elucidation of the catalytic mechanism of natural enzymes. However, challenges arise from the design of catalytic sites, the selection of host molecules, and their integration into active three‐dimensional structures. Herein, we describe the development of a photooxidase mimic by synergetic molecular self‐assembly. 9‐Fluorenylmethyloxycarbonyl‐l‐histidine undergoes efficient co‐assembly with phthalocyanine into nanovesicles with tunable particle size and membrane thickness. The obtained nanovesicles can be used as catalysts for reactive‐oxygen‐mediated photosensitive oxidation with improved effic…

Intrinsic Correlation between Electronic Structure and Degradation: From Few‐Layer to Bulk Black Phosphorus

Black phosphorus (BP) undergoes fast, layer‐dependent degradation in the dark. This process was analyzed by scanning Kelvin probe microscopy and interpreted by considering the Marcus–Gerischer theory (MGT). In the dark, the number of layers, which results in different carrier concentrations, strongly influences the electron transfer rate from BP to oxygen molecules.
AbstractBlack phosphorus (BP) has received much attention owing to its fascinating properties, such as a high carrier mobility and tunable band gap. However, these advantages have been overshadowed by the fast degradation of BP under ambient conditions. To overcome this obstacle, the exact degradation mechanisms need to be unveiled. Herein, we analyzed two sequential degradation processes and the layer‐dependent degradation rates of BP in the dark by scanning Kelvin probe microscopy (SKPM) measurements and theoretical modeling. The layer‐dependent degradation was successfully interpreted by considering the oxidation model b…

Potential‐Induced Fine‐tuning of the Enantioaffinity of Chiral Metal Phases

In for a shock: The electric potential of a mesoporous chiral platinum phase can be tuned to allow quantitative separation of the enantiomers in a tryptophan racemate. An applied potential influences the electrostatic interactions, and thereby the enantioaffinity, between the chiral metal and the target enantiomer.
AbstractConcepts leading to single enantiomers of chiral molecules are of crucial importance for many applications, including pharmacology and biotechnology. Recently, mesoporous metal phases encoded with chiral information have been developed. Fine‐tuning of the enantioaffinity of such structures by imposing an electric potential is proposed, which can influence the electrostatic interactions between the chiral metal and the target enantiomer. This allows the binding affinity between the chiral metal and the target enantiomer to be increased, and thus, the discrimination between two enantiomers to be improved. The concept is illustrated by generating chiral encoded metals i…

A Three‐Membered Cyclic Phosphasilene

The smallest cyclic Si=P species: A phosphorus(I) cation was used as a precursor for the synthesis of the first three‐membered cyclic phosphasilene. The highly strained ring compound can be coordinated to a transition metal through the ylidic phosphorus center or "clicked" with itself to give two cluster‐like Si4P2 isomers.
AbstractSmall unsaturated phosphacycles are versatile reagents owing to their strain and the added functionality of the double bond and the phosphorus lone pair. Herein we report the synthesis and isolation of the smallest possible cyclic phosphasilene as a stable adduct with an N‐heterocyclic carbene (NHC). First reactivity studies show a) that the PSi2 ring is a competent ligand to the Fe(CO)4 fragment via the phosphorus lone pair and b) that the abstraction of the NHC by BPh3 results in the rapid head‐to‐head or head‐to‐tail dimerization of the PSi2 unit. The relatively facile NHC cleavage indicates that the P=Si double bond is available for further man…

Broadband Cr3+, Sn4+‐Doped Oxide Nanophosphors for Infrared Mini Light‐Emitting Diodes

Nanophosphors on display: Mesoporous silica nanoparticles were used as nanocarriers to form the nanophosphor ZnGa2O4:Cr3+,Sn4+ (ZGOCS) in the mesoporous structure after sintering. Good dispersity and morphology can be observed. Good packing density and light conversion efficiency were achieved for a mini‐light emitting diode.
AbstractLight‐emitting diodes break barriers of size and performance for displays. With devices becoming smaller, the materials also need to get smaller. Chromium(III)‐doped oxide phosphors, which emit near‐infrared (NIR) light, have recently been used in small electronic devices. In this work, mesoporous silica nanoparticles were used as nanocarriers. The nanophosphor ZnGa2O4:Cr3+,Sn4+ formed in the mesopore after sintering. Good dispersity and morphology were performed with average diameters of 71±7 nm. It emitted light at 600–850 nm; the intensity was optimized by tuning the doping ratio of Cr3+ and Sn4+. Meanwhile, the light conversion efficiency increased fro…

High iso Aldehyde Selectivity in the Hydroformylation of Short‐Chain Alkenes

The hydroformylation of propene to give predominantly iso‐butanal has been achieved; class‐leading selectivity is possible even at higher temperatures that deliver fast conversion. Racemic rhodium complexes of bidentate phospholane phosphites derived from tropos‐biphenols and unusual solvent systems are the key to the selectivity observed.
AbstractThe hydroformylation of propene to give predominantly iso‐butanal has been achieved; class‐leading selectivity is possible even at higher temperatures that deliver fast conversion. Racemic rhodium complexes of bidentate phospholane phosphites derived from tropos‐biphenols and unusual solvent systems are the key to the selectivity observed.

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Katrina (Kate) Jolliffe

"When I was eighteen I wanted to be a chef. My favorite musicians are Nick Cave and PJ Harvey …" Find out more about Katrina A. Jolliffe in her Author Profile.


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Stereospecific Synthesis of α‐Hydroxy‐Cyclopropylboronates from Allylic Epoxides

Rigid sp3 scaffolds: A catalytic and stereospecific method for the preparation of enantioenriched α‐hydroxy cyclopropylboronates with control in four contiguous stereocenters is described. The reaction involves the borylation of readily available allylic epoxides using an inexpensive CuI salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be selectively prepared.
AbstractHerein, we report a catalytic and stereospecific method for the preparation of enantioenriched α‐hydroxy cyclopropylboronates with control in four contiguous stereocenters. The reaction involves the borylation of readily available allylic epoxides using an inexpensive Cu(I) salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be selectively prepared. Functionalization of the carbon–boron bond provides access to different enantiomerically enriched trisubstituted cyclopropanes from a common i…

Z‐Scheme 2D/2D Heterojunction of Black Phosphorus/Monolayer Bi2WO6 Nanosheets with Enhanced Photocatalytic Activities

A Z‐scheme heterojunction of 2D/2D black phosphorus/monolayer Bi2WO6 was fabricated with enhanced photocatalytic performance under visible light irradiation. The highest NO removal ratio was up to 67 % and the H2 evolution ratio 21 042 μmol g−1. The black phosphorus nanosheets can be used for photocatalytic degradation of exhaust gases in air.
AbstractBlack phosphorus (BP), a star‐shaped two‐dimensional material, has attracted considerable attention owing to its unique chemical and physical properties. BP shows great potential in photocatalysis area because of its excellent optical properties; however, its applications in this field have been limited to date. Now, a Z‐scheme heterojunction of 2D/2D BP/monolayer Bi2WO6 (MBWO) is fabricated by a simple and effective method. The BP/MBWO heterojunction exhibits enhanced photocatalytic performance in photocatalytic water splitting to produce H2 and NO removal to purify air; the highest H2 evolution rate of BP/MBWO is 21042 μmol g−1, is 9.15…

Aliphatic Radical Relay Heck Reaction at Unactivated C(sp3)−H Sites of Alcohols

A selective Heck reaction at β‐, γ‐, and δ‐C(sp3)−H sites of aliphatic alcohols has been developed. The radical hydrogen‐atom transfer/I‐atom translocation process, combined with the palladium‐catalyzed Heck reaction, allows selective remote alkenylation at unactivated C(sp3)−H sites under mild visible‐light‐induced conditions at room temperature. Neither exogenous oxidants nor photosensitizers are necessary.
AbstractThe Mizoroki–Heck reaction is one of the most efficient methods for alkenylation of aryl, vinyl, and alkyl halides. Given its innate nature, this protocol requires the employment of compounds possessing a halogen atom at the site of functionalization. However, the accessibility of organic molecules possessing a halogen atom at a particular site in aliphatic systems is extremely limited. Thus, a protocol that allows a Heck reaction to occur at a specific nonfunctionalized C(sp3)−H site is desirable. Reported here is a radical relay Heck reaction which allows selective remot…

Chiral DMAP‐N‐oxides as Acyl Transfer Catalysts: Design, Synthesis, and Application in Asymmetric Steglich Rearrangement

A DMAP‐N‐oxide, featuring an α‐amino acid as the chiral source, was developed, synthesized and applied in asymmetric Steglich rearrangement. A series of O‐acylated azlactones afforded C‐acylated azlactones possessing a quaternary stereocenter in high yields (88‐97% yields) and excellent enantioselectivities (90‐97% ee). Compared to the widespread use of pyridine nitrogen, which serves as the nucleophilic site in the asymmetric acyl transfer reaction, we discovered that chiral DMAP‐N‐oxides, in which the oxygen now acts as the nucleophilic site, are efficient acyl transfer catalysts. Our finding might open a new door for the development of chiral DMAP‐N‐oxides for asymmetric acyl transfer reactions.

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Rivalry Under Pressure – The Coexistence of Ambient‐pressure Motifs and Close‐packing in Silicon Phosphorus Nitride Imide SiP2N4NH

Non‐metal nitrides such as BN, Si3N4 and P3N5 meet numerous demands on high‐performance materials and their high‐pressure polymorphs exhibit outstanding mechanical properties. Herein, we present the silicon phosphorus nitride imide SiP2N4NH featuring six‐fold coordinated Si. Using the multianvil technique, SiP2N4NH was obtained from high‐pressure high‐temperature synthesis at 8 GPa and 1100 °C with in situ formed HCl acting as a mineralizer. Its structure was elucidated by combination of single‐crystal X‐ray diffraction and solid‐state NMR measurements. Moreover, SiP2N4NH was characterized by energy‐dispersive X‐ray spectroscopy and (temperature‐dependent) powder X‐ray diffraction. The highly condensed Si/P/N framework features PN4 tetrahedra as well as the rare motif of SiN6 octahedra and is discussed in the context of ambient‐pressure motifs competing with close‐packing of nitride anions, representing a missing link in high‐pressure chemistry of non‐metal nitrides.

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Viewpoint Antibacterial Activity of Polymers – Discussions on the Nature of Amphiphilic Balance

We discuss the structure and activity of antibacterial peptides and polymers in the context of "amphiphilic balance" and how these concepts may be applied to some of the new and unusual structures that have been recently published. We find that the central concept of amphiphilic balance ‐ appropriately adjusting the cationic and hydrophobic nature of the polymer chains ‐ can be achieved in myriad ways. Whereas the conventional approaches typically involved pendant linear alkyl groups in the polymer side chains, some recent examples have shown that hydrophobic polymer backbones also play an important role in dictating the amphiphilic properties of the polymer chains. We believe these additional concepts expand the cannon of amphiphilic balance as a design paradigm in the field of antibacterial polymers that mimic the activity of host defense peptides.

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Water and Sodium Chloride: Essential Ingredients for Robust and Fast Pd‐Catalysed Cross‐Coupling Reactions between Organolithium Reagents and (Hetero)aryl Halides

Just add salt! Water with added NaCl was a very effective reaction medium for performing direct and fast (within 20 s) Pd‐catalysed cross‐coupling reactions between organolithiums and a variety of (hetero)aryl halides at room temperature and under air. Catalyst and water recyclability and reusability were added advantages of the proposed protocol.
AbstractDirect palladium‐catalysed cross‐couplings between organolithium reagents and (hetero)aryl halides (Br, Cl) proceed fast, cleanly and selectively at room temperature in air, with water as the only reaction medium and in the presence of NaCl as a cheap additive. Under optimised reaction conditions, a water‐accelerated catalysis is responsible for furnishing C(sp3)–C(sp2), C(sp2)–C(sp2), and C(sp)–C(sp2) cross‐coupled products, in competition with protonolysis, within a reaction time of 20 s, in yields of up to 99 %, and in the absence of undesired dehalogenated/homocoupling side products even when challenging secondary organolithiums s…

A Metastable Crystalline Phase in Two‐Dimensional Metallic Oxide Nanoplates

The metastablebctphase was only observed in ultrathin cerium oxide nanoplates. Thermodynamic energy analysis confirmed that the surface energy of the ultrathin nanoplates is the cause of the remarkable stabilization of the metastable bct phase. The mechanism of surface energy regulation can be expanded to other metallic oxides, thus providing a means for manipulating and stabilizing such materials under ambient conditions.
AbstractA simple method was adopted in which ultrathin cerium oxide nanoplates (<1.4 nm) were synthesized to increase the surface atomic content, allowing transformation from a face‐centered cubic (fcc) phase to a body‐centered tetragonal (bct) phase. Three types of cerium oxide nanoparticles of different thicknesses (1.2 nm ultrathin nanoplates, 2.2 nm nanoplates, and 5.4 nm nanocubes) were examined using transmission electron microscopy and X‐ray diffraction. The metastable bct phase was observed only in ultrathin nanoplates. Thermodynamic energy analysis confir…

Enantioselective Aluminum‐Free Alkene Hydroarylations through C−H Activation by a Chiral Nickel/JoSPOphos Manifold

SPO rules: A chiral Ni/SPO regime enabled outstanding levels of enantio‐control in asymmetric C−H alkylations with unactivated alkenes.
AbstractHighly enantioselective nickel‐catalyzed alkene endo‐hydroarylations were accomplished with full selectivity by organometallic C−H activation. The asymmetric assembly of chiral six‐membered scaffolds proved viable in the absence of pyrophoric organoaluminum reagents within an unprecedented nickel/JoSPOphos manifold.

from A via a.sfakia on Inoreader http://bit.ly/2HgJv1h

Base‐Mediated Defluorosilylation of C(sp2)−F and C(sp3)−F Bonds

Base motive: A base‐promoted defluorosilylation of unactivated C(sp2)−F and C(sp3)−F bonds, obviating the need for transition‐metal catalysis, specialized ligands, or harsh reaction conditions, has been developed. The salient features of this method are the mild reaction conditions, ease of execution, and wide substrate scope, even within the context of late‐stage functionalization of advanced fluorinated building blocks, thus offering a complementary reactivity mode to existing silylation technologies.
AbstractThe ability to selectively forge C–heteroatom bonds by C−F scission is typically accomplished by metal catalysts, specialized ligands and/or harsh reaction conditions. Described herein is a base‐mediated defluorosilylation of unactivated C(sp2)−F and C(sp3)−F bonds that obviates the need for metal catalysts. This protocol is characterized by its simplicity, mild reaction conditions, and wide scope, even within the context of late‐stage functionalization, constituting a complemen…

Chiral Lithium Amido Aryl Zincates: Simple and Efficient Chemo‐ and Enantio‐Selective Aryl Transfer Reagents

Chemo‐ and enantio‐selective nucleophilic aryl transfer: The key reactant is a chiral tricoordinated lithium amido aryl zincate of which the chiral appendage is simply recovered and reused. The arylation leaves intact sensitive functions such as esters, nitriles, ketones or enolisable sites, while running with aldehyde groups in good yields and high ee values, this whatever the ortho, meta, or para substituent borne by the substrate if aromatic.
AbstractAn enantioselective aryl transfer is promoted using chiral tricoordinated lithium amido aryl zincates that are easily accessible reagents and whose chiral appendage is simply recovered for reuse. The arylation reaction is run in good yields (60 % average on twenty substrates) and high enantiomeric excesses (95 % ee average). This occurs whatever the ortho, meta, or para substituent borne by the substrate and a complete chemoselectivity is observed with respect to the aldehyde function. Sensitive groups such as nitriles, esters, ketones,…

Digging into the Sequential Space of Thiolactone Precision Polymers: A Combinatorial Strategy to Identify Functional Domains

Sequence coins function: Sequences that bind m‐THPC are selected from a library of thiolactone (Tla)/Michael oligomers by single‐bead readout with MALDI‐TOF MS/MS. The corresponding Tla/Michael‐PEG conjugates make m‐THPC available in solution and allow drug payload as well as drug release kinetics to be fine‐tuned by sequence variation in the precision segment.
AbstractFunctional sequences of precision polymers based on thiolactone/Michael chemistry are identified from a large one‐bead one‐compound library. Single‐bead readout by MALDI‐TOF MS/MS identifies sequences that host m‐THPC that is a second generation photo‐sensitizer drug. The corresponding Tla/Michael‐PEG conjugates make m‐THPC available in solution and drug payload as well as drug release kinetics can be fine‐tuned by the precision segment.

from A via a.sfakia on Inoreader http://bit.ly/2RShC3U