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The templated synthesis of hydroxyapatite (HAP) nanowires@metal-organic framework (MOF) core/shell nanofibers (named HAP@MIL-100(Fe) nanofibers) is demonstrated. The ultralong hydroxyapatite nanowires are adopted as a hard template for the nucleation and growth of MIL-100(Fe) (a typical MOF) through the layer-by-layer method. The Coulombic and chelation interactions between Ca2+ ions on the surface of the HAP nanowires and the COO− organic linkers of MIL-100(Fe) play key roles in the formation process. The as-prepared, water-stable HAP@MIL-100(Fe) nanofibers exhibit peroxidase-like activity toward the oxidation of different peroxidase substrates in the presence of H2O2, accompanied by a clear color change of the solution. Furthermore, a flexible, recyclable HAP@MIL-100(Fe) test paper is prepared successfully by using HAP@MIL-100(Fe) nanofibers as building blocks. A simple, low-cost, and sensitive colorimetric method for the detection of H2O2 and glucose is established based on the as-prepared, flexible, recyclable HAP@MIL-100(Fe) test paper. More importantly, the HAP@MIL-100(Fe) test paper can be recovered easily for reuse by simply dipping in absolute ethanol for just 30 min, thus showing excellent recyclability. With its combination of advantages such as easy transportation, easy storage and use, rapid recyclability, light weight, and high flexibility, this HAP@MIL-100(Fe) test paper is promising for wide applications in various fields. [ABSTRACT FROM AUTHOR]

The templated synthesis of ultralong hydroxyapatite nanowires@metal–organic framework core/shell (HAP@MIL‐100(Fe)) nanofibers has been demonstrated herein. The HAP@MIL‐100(Fe) nanofibers exhibited peroxidase‐like activity towards the oxidation of different peroxidase substrates in the presence of H2O2 accompanying with the clear color change of the solution. A new kind of flexible test paper was prepared by using HAP@MIL‐100(Fe) nanofibers as building blocks, which can be used for the detection of H2O2 and glucose, and it can be easily recovered, exhibiting excellent recyclability and promising applications in various fields. More information can be found in the Full Paper by Y.‐J. Zhu and Z.‐C. Xiong et al. on page 3328 ff. [ABSTRACT FROM AUTHOR]

Nitrogen-doped porous carbon nanosheets were prepared from eucalyptus tree leaves by simply mixing the leaf powders with KHCO3 and subsequent carbonisation. Porous carbon nanosheets with a high specific surface area of 2133 m2 g−1 were obtained and applied as electrode materials for supercapacitors and lithium ion batteries. For supercapacitor applications, the porous carbon nanosheet electrode exhibited a supercapacitance of 372 F g−1 at a current density of 500 mA g−1 in 1 m H2SO4 aqueous electrolyte and excellent cycling stability over 15 000 cycles. In organic electrolyte, the nanosheet electrode showed a specific capacitance of 71 F g−1 at a current density of 2 Ag−1 and stable cycling performance. When applied as the anode material for lithium ion batteries, the as-prepared porous carbon nanosheets also demonstrated a high specific capacity of 819 mA h g−1 at a current density of 100 mA g−1, good rate capability, and stable cycling performance. The outstanding electrochemical performances for both supercapacitors and lithium ion batteries are derived from the large specific surface area, porous nanosheet structure and nitrogen doping effects. The strategy developed in this paper provides a novel route to utilise biomass-derived materials for low-cost energy storage systems. [ABSTRACT FROM AUTHOR]

There has been a recent upsurge in the study and application of approaches utilizing cyclotriphosphate 1 (cyclo‐TP, also known as trimetaphosphate, TMP) and/or proceeding through its analogues in synthetic chemistry to access modified oligo‐ and polyphosphates. This is especially useful in the area of chemical nucleotide synthesis, but by no means restricted to it. Enabled by new high yielding and easy‐to‐implement methodologies, these approaches promise to open up an area of research that has previously been underappreciated. Additionally, refinements of concepts of prebiotic phosphorylation chemistry have been disclosed that ultimately rely on cyclo‐TP 1 as a precursor, placing it as a potentially central compound in the emergence of life. Given the importance of such concepts for our understanding of prebiotic chemistry in combination with the need to readily access modified polyphosphates for structural and biological studies, this paper will discuss selected recent developments in the field of cyclo‐TP chemistry, briefly touch on ultraphosphate chemistry, and highlight areas in which further developments can be expected. [ABSTRACT FROM AUTHOR]

Heterogenized photoredox catalysts provide a path for sustainable chemical synthesis using highly tunable, reusable constructs. Here, heterogenized iridium complexes as photoredox catalysts were assembled via covalent attachment to metal oxide surfaces (ITO, ZrO2, Al2O3) in thin film or nanopowder constructs. The goal was to understand which materials provided the most promising constructs for catalysis. To do this, reductive dehalogenation of bromoacetophenone to acetophenone was studied as a test reaction for system optimization. All catalyst constructs produced acetophenone with high conversions and yields with the fastest reactions complete in fifteen minutes using Al2O3 supports. The nanopowder catalysts resulted in faster and more efficient catalysis, while the thin film catalysts were more robust and easily reused. Importantly, the thin film constructs show promise for future photoelectrochemical and electrochemical photoredox setups. Finally, all catalysts were reusable 2–3 times, performing at least 1000 turnovers (Al2O3), demonstrating that heterogenized catalysts are a sustainable catalyst alternative. [ABSTRACT FROM AUTHOR]

Choosing the optimal catalyst for a new transformation is challenging because the ideal molecular requirements of the catalyst for one reaction do not always simply translate to another. Large groups at the 3,3′ positions of the binaphthol rings are important for efficient stereoinduction but if they are too large this can lead to unusual or poor results. By applying a quantitative steric assessment of the substituents at the 3,3′ positions of the binaphthol ring, we have systematically studied the effect of modulating this group on enantioselectivity for a wide range of reactions involving imines, and verified this analysis using ONIOM calculations. We have shown that in most reactions, the stereochemical outcome depends on both proximal and remote sterics. Summarising detailed calculations into a simple qualitative model identifies and explains the steric features required for high selectivity. This model is consistent with seventy seven papers reporting reactions (over 1000 transformations in total), and provides a straightforward decision tree for selecting the best catalyst. [ABSTRACT FROM AUTHOR]

Elucidating the effects of oligosaccharides on glycoprotein properties, such as local conformational changes, stability, and dynamics, has still been challenging. In this paper, a novel partial 15N-labeling method for the amide backbone of a synthetic glycoprotein is proposed. Using solid-phase peptide synthesis (SPPS) and native chemical ligation (NCL), thirteen 15N-labeled amino acids were inserted at specific positions of the protein backbone, while intentionally varying the enrichment of 15N atoms. This idea discriminated even the same type of amino acid based on the intensities of 1H-15N HSQC signals, combined with classic homonuclear TOCSY and NOESY methods, thus allowing for understanding the dynamics of the local conformation of a synthetic homogeneous glycoprotein. Results suggested that the attachment of an oligosaccharide of either a bi-antennary complex-type or a high-mannose-type did not disturb protein conformation. However, T1 values suggested that the oligosaccharide influenced dynamics at the local conformation. Temperature-varied circular dichroism (CD) spectra and T1 values clearly indicated that oligosaccharides appeared to inhibit protein fluctuation or, in other words, stabilize protein structure. This insight into oligosaccharide behavior suggests some further effects on binding affinity between a glycoprotein and its receptor. [ABSTRACT FROM AUTHOR]

Campestarenes are a new family of Schiff-base macrocycles that form selectively in a one-step synthesis. These macrocycles with five-fold symmetry show solvent-dependent tautomerization and dimerization or aggregation. In this paper, we have prepared new soluble campestarenes that do not aggregate. The initial single-crystal X-ray diffraction study of a campestarene reveals that these macrocycles are nearly flat. The tautomeric behavior of the campestarenes has been extensively studied by variable-temperature, multinuclear NMR spectroscopy, UV/Vis spectroscopy, and IR spectroscopy. In polar solvents, such as DMF, the molecules exist predominantly in their keto-enamine form, but the enol-imine tautomer is dominant in non-polar solvents. A detailed computational study of the tautomeric forms of campestarenes provides a theoretical basis for their behavior and corroborates the experimental data. The results of this study give the first comprehensive understanding of the electronic and spectroscopic properties of these pentagonal macrocycles. [ABSTRACT FROM AUTHOR]

The article abstracts of various research papers that were recently been published in sister journals of the "Chemistry: A European Journal," including papers on synthesis of lactones, biosynthesis of lactic acid and homogeneous catalysis.

Both the biosynthesis as well as the chemical synthesis of pyrronazol follow a modular approach starting with a pyrrole building block. This secondary metabolite was isolated from Nannocystis pusilla Ari7 and both routes utilize modular extensions to introduce an oxazole moiety and to generate the unsaturated lactone through ester condensation steps. For more information see the Full Paper by M. Kalesse et al. on page 15917 ff. [ABSTRACT FROM AUTHOR]

Simple particle counting cannot in general be reliably employed to predict the observed architecture as DFT analysis shows that vibrational contributions to entropy dominate and may significantly influence the preferred architecture. However, simple particle counting, which predicts triangles over squares, is seen to be correct here, and DFT confirms the triangles are energetically favored over the corresponding squares. Image kindly created by Michael Crawford (Dunedin). More information can be found in the Full Paper by A. L. Garden, S. Brooker et al. on page 14193. [ABSTRACT FROM AUTHOR]

Interstellar! The modular synthesis and characterization of several substituted N ‐ hetero benzenacyclooctaphanes, a new motif for heteroaromatic conjugated cycles, is presented. The graphic illustrates the versatility of our system, demonstrated by several crystal structures of our target molecules. These were synthesized by condensation of substituted aromatic ortho ‐ diamines with a cyclic octaketone building block. More information can be found in the Full Paper by U. H. F. Bunz et al. on page 10543. [ABSTRACT FROM AUTHOR]

This paper reports on the development of an efficient synthesis of enantiopure phospha[6]helicenes through a [2+2+2] alkyne cyclotrimerization reaction. The corresponding gold complexes proved to be highly efficient both in terms of catalytic activity and enantioselectivity in [2+2] and [4+2] cycloaddition reactions. Furthermore, in the presence of an external nucleophile, such as water or alcohols, the tandem cyclization/addition reactions take place in high yields and excellent diastereo- and enantioselectivities. [ABSTRACT FROM AUTHOR]

Metallic nanomaterials displaying hollow interiors as well as sharp tips/branches at their surface (such as hollow nanodendrites) are attractive, because these features enable higher surface-to-volume ratios than their solid and/or rounded counterparts. This paper describes a simple strategy for the synthesis of Ag-Au nanodendrites in 15 s using Ag nanospheres prepared in a previous synthetic step as seeds. Our approach was based on the utilization of Ag nanospheres as seeds for Au deposition by a combination of galvanic replacement reaction between Ag and AuCl4−(aq) and AuCl4−(aq) reduction using hydroquinone in the presence of polyvinylpyrrolidone (PVP) as a stabilizer and water as the solvent. The produced Ag-Au nanodendrites presented monodisperse sizes, and their surface morphologies could be tuned as a function of growth time. Owing to their hollow interiors and sharp tips, the Ag-Au nanodendrites performed as effective substrates for surface-enhanced Raman scattering (SERS) detection of 4-MPy (4-mercaptopyridine) and R6G (rhodamine 6G) as probe molecules. We believe that the approach described herein can serve as a protocol for the fast and one-step synthesis of Ag-Au hollow nanondendrites with a wide range of sizes, compositions, and surface morphologies for applications in SERS and catalysis. [ABSTRACT FROM AUTHOR]

A new seedless method is reported for synthesizing monodispersed gold nanorods (AuNRs) with a remarkably high yield (≈100%) and highly tunable longitudinal surface plasmon resonance (LSPR). The soft‐template modification and well‐controlled growth kinetics synergistically influence the nanorod growth, providing an effective strategy for synthesizing monodispersed AuNRs with different dimensions. For more detail, see the Full Paper by H. Wang and co‐workers on page 3291 ff. [ABSTRACT FROM AUTHOR]

A sulfur ‐ bridged inorganic macrocycle and a room temperature singlet biradicaloid dianion have been isolated in the Wurtz reduction of a mixture of cis ‐ and trans ‐ dichlorophosph(V)azane. It appears that these products from the same reaction are the outcome of two different reduction pathways. This approach may facilitate the discovery of new types of inorganic macrocycles and new polymeric assemblies similar to those observed in this work. More information can be found in the Full Paper by S. Singh, D. S. Wright et al. on page 12027 ff. [ABSTRACT FROM AUTHOR]

1,3a,6a‐Triazapentalene (TAP) is a compact fluorescent molecule consisting of a triazabicyclo[3.3.0]octane skeleton. In this work, a method of synthesizing a directly connected TAP ring system as a linearly bonded aromatic system with a planar form was established. The TAP‐bonded system showed interesting fluorescence properties resulting from changes in aggregation state at high concentration and solid state. In particular, solids of some TAP‐bonded systems showed changes in fluoresence color by grinding, that is, typical mechanochromic fluorescence properties were observed. The cover picture shows that fluorescence is emitted when the DJ scrapes the TAP‐bonded system represented by disks. More information can be found in the Full Paper by K. Namba et al. on page 17727. [ABSTRACT FROM AUTHOR]

Structural reassignment: Total synthesis of the proposed and correct structures of (−) ‐ lyngbyaloside B (see figure), a marine macrolide glycoside, has been achieved. The synthesis entailed an Abiko – Masamune aldol reaction, a vinylogous Mukaiyama aldol reaction, and an acyl ketene macrocyclization to forge the 14 ‐ membered macrolactone. The present work established the complete stereostructure of this natural product in an unambiguous manner. More information can be found in the Full Paper by H. Fuwa et al. on page 6815 ff. [ABSTRACT FROM AUTHOR]

Carbonate Halides Three new carbonate halides, Cs3Pb2(CO3)3I (CPCI), KBa2(CO3)2F (KBCF), and RbBa2(CO3)2F (RBCF) are reported by Y. Yang, Z. Yang, S. Pan et al. in their Full Paper on page 2944 ff. CPCI features a 2D layered structure, which, owing to the arrangement of CO3 units and the stereoactive Pb2+, displays moderate birefringence. KBCF and RBCF adopt a honeycomb‐like framework. Through comparison of these structures with other carbonate fluorides, it is illustrated that the quantity and distribution of O atoms and the position of divalent cations play essential roles in determining the arrangement of CO3 groups. [ABSTRACT FROM AUTHOR]

Tumour cell migration can be stopped by small molecules such as migrastatin, a natural product that inhibits tumour cell migration (μM range) in vitro. In their Full Paper on page 18109 ff., P. Murphy et al. describe the synthesis and structure – activity studies of migrastatin and its analogues. Compounds were tested in vitro against both breast and pancreatic cancer cell lines and inhibition of tumour cell migration was observed in both wound ‐ healing (scratch) and Boyden chamber assays, with one analogue showing low affinity for a range of secondary drug targets, indicating it is at low risk of displaying adverse side effects. [ABSTRACT FROM AUTHOR]

The Yin – Yang symbol. on the cover symbolizes the complementary nucleophilic and electrophilic ligand arms of the new cooperative PNN pincer ligand, strengthened by the two Kung ‐ Fu fighters making balancing, harmonizing moves. For more details see the Full Paper by J. I. van der Vlugt, B. de Bruin et al. on page 12683 ff. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue is the group of Bas de Bruin and Jarl Ivar van der Vlugt at the University of Amsterdam. The image depicts the complementary nucleophilic and electrophilic ligand arms of a new cooperative PNN pincer ligand. Read the full text of the article at . [ABSTRACT FROM AUTHOR]

Abstract: The reaction of [(Cp′′′Co)2(μ,η2:2‐As2)2] with the decamethylsamarocenes [Cp*2Sm(THF)2] or [Cp*2Sm], or the bis(tetramethyl‐n‐propyl)samarocene [(C5Me4(n‐propyl))2Sm] resulted in the mixed d/f polyarsenides [(Cp′′′Co)2As4Sm(η5‐C5Me4R)2] (R=Me, n‐propyl). They are the first structural representatives of open chain‐like polyarsenides as ligands in the coordination sphere of lanthanides. Their formation can be explained by an intramolecular As–As coupling within the cobalt polyarsenide complex after reduction by the divalent samarium complex. Density functional theory calculations give insight into the structural change of the (As2)2 unit in [{Cp′′′Co(μ,η2:2‐As2)}2] upon reduction. [ABSTRACT FROM AUTHOR]

Abstract: Three hetero‐biradical derivatives, with the structure of a back‐to‐back connected benzotriazinyl and tetramethyl or tetraethylisoindoline N‐oxyl sharing a common benzo ring, 3‐tert‐butyl‐1‐phenyl‐1,4,6,8‐tetrahydro‐6,6,8,8‐tetramethyl‐pyrrolo[4,5‐g]‐1,2,4‐benzotriazin‐4‐yl‐7‐oxyl (1‐tBu), 1,3‐diphenyl‐1,4,6,8‐tetrahydro‐6,6,8,8‐tetramethyl‐pyrrolo[4,5‐g]‐1,2,4‐benzotriazin‐4‐yl‐7‐oxyl (1‐Ph), and 3‐tert‐butyl‐1‐phenyl‐1,4,6,8‐tetrahydro‐6,6,8,8‐tetraethyl‐pyrrolo[4,5‐g]‐1,2,4‐benzotriazin‐4‐yl‐7‐oxyl (2‐tBu), were synthesized and characterized by single‐crystal X‐ray analyses, variable‐temperature magnetic susceptibility studies, and DFT calculations. Temperature dependences of the magnetic susceptibilities of 1‐tBu, 1‐Ph, and 2‐tBu exhibit broad maxima at 70, 71, and 43 K, respectively. Although these radical derivatives form a columnar or chained assembly in the solid state, magnetic measurements of diluted samples in the polymer matrices and computational results imply that the magnetic properties of the polycrystalline sample can be explained by a two‐spin system with an intramolecular antiferromagnetic interaction. The magnetic behavior can be reproduced by using the Bleaney–Bowers model, with 2J=−80.0 cm−1 for 1‐tBu, 2J=−77.1 cm−1 for 1‐Ph, and 2J=−48.9 cm−1 for 2‐tBu. The moderately strong intramolecular antiferromagnetic interactions can be interpreted by a through‐bond interaction through the nonconjugated framework and/or through‐space interactions based on molecular orbital theory. The strong distance dependency between the N−O spin site and vinylic carbon atoms indicates that the orbital interaction plays an important role in the intramolecular magnetic interaction. The reduced magnetic interaction in 2‐tBu relative to those of 1‐tBu and 1‐Ph can be attributed to restricted rotation of the tetraethyl group. [ABSTRACT FROM AUTHOR]

A multiscale approach has been used to link metal ‐ ion coordination with nanoscale structure to reveal the free ‐ energy balance that drives the phase transfer of neutral metal salts. This study gives structural insight into the intricate relationship between the hard metal ‐ ion complexation interactions and the soft long ‐ range interactions between aggregates. The cover art (by Sana Sandler, Argonne National Laboratory) depicts a malonamide amphiphile, which has been used to extract Eu(NO3)3 from water into oil, through the water – oil interface. Such metal separation techniques are important in the efficient reprocessing of nuclear waste and the refining of rare ‐ earth elements. For more details, see the Full Paper by R. J. Ellis, L. Berthon, P. Guilbaud et al. on page 12796 ff. [ABSTRACT FROM AUTHOR]

The nuclear magnetic resonance (NMR) detectability of several TB‐relevant agents have been significantly improved through the use of the parahydrogen‐based hyperpolarization protocol signal amplification by reversible exchange (SABRE) in conjunction with the 2H‐labelling of key sites within their molecular structures and the 2H‐labelling of the magnetization‐transfer catalyst. The T1 relaxation times and polarization levels of these agents are quantified under test conditions to produce a protocol to identify structurally optimized motifs for future detection in MRI. For more information see the Full Paper by S. B. Duckett et al. on page 16990 ff. [ABSTRACT FROM AUTHOR]

Multiblock copolymers: A new method to synthesize functional multiblock copolymers composed of alternately aligned sequential peptides and vinyl polymers is described. Cyclic oligopeptides containing an alkoxyamine bond in the framework have been developed as an initiator for NMP. Radical polymerization by this type of initiator enables multiple peptide blocks to be directly inserted into the vinyl polymer backbone during the polymerization. Folding behavior of the resultant multiblock peptide–polymer hybrid is also demonstrated. For more information see the Full Paper by N. Higashi, T. Koga, et al. on page 15050 ff. [ABSTRACT FROM AUTHOR]

Introduction of alkoxy protecting groups into the vacant sites of lacunary polyoxometalates (POMs) was demonstrated. By reacting organic‐solvent‐soluble trivacant lacunary Keggin‐type POMs with methanol, six methoxy groups were introduced into the vacant sites. These monodentate alkoxy ligands could protect the reactive vacant sites and also easily be dissociated by hydrolysis. In contrast, the multidentate alkoxy ligands of pentaerythritol showed high resistance against hydrolysis, which allowed the synthesis of dimeric inorganic–organic–inorganic hybrid structures with the same or different heteroatoms. More information can be found in the Full Paper by K. Suzuki, N. Mizuno et al. on page 14213. [ABSTRACT FROM AUTHOR]

Modular access to a range of tailored heterocyclic scaffolds with diverse 3D‐complexity is provided by a novel cascade one‐pot methodology based on Pictet–Spengler/aza‐Michael addition and Schiff base/aza‐Michael addition/reduction protocols. The versatile approach is highly diastereoselectivity and provides direct access to drug‐like molecules in good yields. The large substrate scope will enable broad coverage of chemical space and allow for rapid SAR exploration. For more information see the Full Paper by R. Mazitschek, T. H. Al‐Tel, et al. on page 14182 ff. [ABSTRACT FROM AUTHOR]

Subsequent reactions of a neutral phosphenium complex of Mn with H− and H+ sources resulted in a stoichiometric H2 addition to the Mn=P double bond, which can be reversed upon thermal or photochemical excitation. In contrast, in the reaction with NH3BH3, the same complex acted as dehydrogenation catalyst. DFT studies suggested to explain this transformation as a ligand ‐ centred process, in which the H+/H− pair is picked up by the phosphenium ligand and the metal is mainly a spectator. Apart from being the first application of a phosphenium complex in catalysis, this discovery adds a new twist to the further development of ligand ‐ centred reactivity and the use of metal complexes in catalysis. More information can be found in the Full Paper by D. Gudat et al. on page 11560. [ABSTRACT FROM AUTHOR]

The universe of donor and acceptor building blocks is often nonluminescent. However, if linked together by our protection ‐ group ‐ free Suzuki coupling as an ignition we can efficiently launch electronically diverse functional donor – acceptor molecules. A colorful “glow in the dark” property can be introduced from the unique electron acceptor 9 ‐ hydroxyphenalenone and suitable π ‐ donors. This results in tunable luminophores with interesting functionalities and electronic properties. More information can be found in the Full Paper by T. J. J. Müller et al. on page 10551. [ABSTRACT FROM AUTHOR]

The evolutionary tale of palladium‐based catalysts for selective alkyne hydrogenation, from bare to lead‐alloyed, and, most recently, ligand‐modified nanoparticles, is unlocked using flow chemistry. Distinctions in the performance of each catalyst system as well as accessibility constraints arising from the use of ligands are identified and rationalized. For more details, see the Full Paper by J. Pérez‐Ramírez, N. López et al. on page 5926 ff. [ABSTRACT FROM AUTHOR]

Plant research is hampered in several aspects by a lack of pure oligosaccharide samples that closely represent structural features of cell wall glycans. An alternative to purely chemical synthesis to access these oligosaccharides is chemo‐enzymatic synthesis using glycosynthases. These enzymes enable the ligation of oligosaccharide donors, when activated for example as α‐glycosyl fluorides, with suitable acceptor oligosaccharides. Herein, the synthesis of xylan oligosaccharides up to dodecasaccharides is reported, with glycosynthase‐mediated coupling reactions as key steps. The xylo‐oligosaccharide donors were protected at the non‐reducing end with a 4‐O‐tetrahydropyranyl (THP) group to prevent polymerization. Installation of an unnatural 3‐O‐methylether substituent at the reducing end xylose of the oligosaccharides ensured good water solubility. Biochemical assays demonstrated enzymatic activity for the xylan acetyltransferase XOAT1 from Arabidopsis thaliana, xylan arabinofuranosyl‐transferase XAT3 enzymes from rice and switchgrass, and the xylan glucuronosyltransferase GUX3 from Arabidopsis thaliana. In case of the glucuronosyltransferase GUX3, MALDI‐MS/MS analysis of the reaction product suggested that a single glucuronosyl substituent was installed primarily at the central xylose residues of the dodecasaccharide acceptor, demonstrating the value of long‐chain acceptors for assaying biosynthetic glycosyltransferases. [ABSTRACT FROM AUTHOR]

As a demonstration of an alternative to the challenges faced with batch pharmaceutical manufacturing including the large production footprint and lengthy timescale, we previously reported a refrigerator-sized continuous flow system for the on-demand production of essential medicines. Building on this technology, herein we report a second-generation, reconfigurable and 25% smaller (by volume) continuous flow pharmaceutical manufacturing platform featuring advances in reaction and purification equipment. Consisting of two compact [0.7 (L) Χ 0.5 (D) Χ 1.3m (H)] stand-alone units for synthesis and purification/ formulation processes, the capabilities of this automated system are demonstrated with the synthesis of nicardipine hydrochloride and the production of concentrated liquid doses of ciprofloxacin hydrochloride, neostigmine methylsulfate and rufinamide that meet US Pharmacopeia standards. [ABSTRACT FROM AUTHOR]

Peptidotriazolamers are hybrid foldamers combining features of peptides and triazolamers--repetitive peptidomimetic structures with triazoles replacing peptide bonds. We report on the synthesis of a new class of peptidomimetics, containing 1,5-disubstituted 1,2,3-triazoles in an alternating fashion with amide bonds and the analysis of their conformation in solid state and solution. Homo- or heterochiral peptidotriazolamers were obtained from enantiomerically pure propargylamines with stereogenic centers in the propargylic position and a-azido esters by ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) under microwave conditions in high yields. With such building blocks the peptidotriazolamers are readily available by solution phase synthesis. While the conformation of the homochiral peptidotriazolamer Boc-Ala[5Tz]Phe-Val[5Tz]Ala-Leu[5Tz]Val-OBzl resembles that of a β VIa1 turn, the heterochiral peptidotriazolamer Boc-d-Ala[5Tz]Phe-d-Val[5Tz]Ala-d-Leu[5Tz]Val-OBzl adopts a polyproline-like repetitive structure. [ABSTRACT FROM AUTHOR]

The [4+2] cycloaddition reaction between 2- pyrone and Me3Si-C≡P gives the corresponding 2-(trimethylsilyl)- λ3-phosphinine in good yields as a rather air and moisture stable, colorless oil. Insight into the regioselectivity of the pericyclic reaction was obtained with the help of deuterium- labeling experiments. The silyl-phosphinine acts as a ligand for the preparation of a Cu(I) and the first crystallographically characterized phosphinine-Ag(I) complex. The title compound was further used as a starting material for an alternative preparation of the parent phosphinine C5 H5P by means of protodesilylation with HCl. C5 H5P reacts with CuBr∙S(CH3 )2 to give an infinite Cu(I)Br coordination polymer. DFT calculations shed light on the influence of the -Si(CH3)3 group on the electronic properties of the aromatic phosphorus heterocycle. [ABSTRACT FROM AUTHOR]

An amine-containing non-interpenetrating pillar-layer framework, [Zn2(dbtcb)( L1)] ⋅ x solvent ( 1), has been synthesized from Zn(NO3)2 and the ligands 1,4-dibromo-2,3,5,6-tetrakis(4-carboxyphenyl)benzene (H4DBTCB) and 2,5-bis(4-pyridyl)aniline ( L1). The [Zn2(COO)4] secondary building units (SBUs) are bridged by DBTCB to form two-dimensional layers that are linked by L1 ligands acting as pillars to form a three-dimensional network. This NH2-containing framework can undergo versatile tailoring through post-synthetic covalent modification, solvent-assisted linker exchange (SALE), and single-crystal-to-single-crystal (SC-SC) transmetalation reactions. Acetamide-functionalized [Zn2( L2)(dbtcb)] ⋅ xsolvent ( 2) could be obtained by direct synthesis from Zn(NO3)2, N-acetyl-2,5-bis(4-pyridyl)aniline ( L2) and H4DBTCB. Importantly, compound 1 with pure NH2 ligands as pillars could be obtained by SALE of 2 with L1 in DMSO solution. The transmetalation reactions of 1 with CuII, NiII, and CoII were studied; inductively coupled plasma-atomic emission (ICP) analysis revealed that 1 underwent almost complete SC-SC transmetalation with CuII within 30 h, whereas with NiII and CoII only 70 and 80 % substitutions were achieved. Photoluminescence studies revealed that 1 and 2 display yellow-green and UV emission, respectively, under a UV lamp. Furthermore, the photoluminescent properties could be tuned by introducing mixed pillar amino ligands L1 and L2 into the MOF to produce multivariate (MTV) MOF 3 displaying overall orange emission. [ABSTRACT FROM AUTHOR]

Equipping silicon(IV) with electron-rich, geometrically constrained NNN- and ONO-tridentate substituents leads to aminosilanes with increased Lewis acidity-expressed through the formation of Si2N2 rings by head-to-tail dimerization. Depending on the substituents, the dimerization can be controlled for the first time, yielding monomeric, structurally reversible and dimeric states. The monomeric species display substantial distortions from tetrahedral towards planar geometry at silicon. The dimerization and the Lewis acidity of aminosilanes are rationalized by (conceptual) DFT, NBO, ETS-NOCV and QTAIM methods. The preorganization at silicon, London dispersion between the substituents and resonance phenomena inside the formed Si2N2 tetracycles are identified as driving forces for the dimerization. Comparison with selected aminosilanes permits general conclusions to be reached on the Lewis acidity of silicon species and on the aggregation of amphiphilic compounds. [ABSTRACT FROM AUTHOR]

Herein we describe the synthesis, and computationally aided photophysical characterization of a new set of urea-bridged bis-BODIPY derivatives. These new dyads are efficiently obtained by a one-pot tandem Staudinger/aza-Wittig ureation protocol, from easily accessible meso-phenyl ortho-azidomethyl BODIPYs. These symmetric bis-BODIPYs outstand by a high absorption probability and excellent fluorescence and laser emission in less polar media. Nevertheless, this emission ability decreases in more polar media, which is ascribed to a light-induced charge-transfer from the urea spacer to the dipyrrin core, a process that can be modulated by appropriate changes in the substitution pattern of the BODIPY core. Furthermore, this ureation protocol can also be employed for the direct conjugation of our BODIPY-azides to amine-containing compounds, thus providing access to fluorescent non-symmetric ureas. [ABSTRACT FROM AUTHOR]

A new and simple approach is reported for the synthesis of uniformly dispersed PtPd alloy nanocatalysts supported on graphene nanoplatelets (GNPs) (PtPd-GNPs) through the introduction of bifunctional materials, which can modify the GNP surface and simultaneously reduce metal ions. With the use of poly(4-styrenesulfonic acid), poly(vinyl pyrrolidone), poly(diallyldimethylammonium chloride), and poly(vinyl alcohol) as bifunctional materials, PtPd-GNPs can be produced through a procedure that is far simpler than previously reported methods. The as-prepared nanocrystals on GNPs clearly exhibit uniform PtPd alloy structures of around 2 nm in size, which are strongly anchored and well distributed on the GNP sheets. The Pt/Pd atomic ratio and loading density of the nanocrystals on the GNPs are controlled easily by changing the metal precursor feed ratio and the mass ratio of GNP to the metal precursor, respectively. As a result of the synergism between Pt and Pd, the as-prepared PtPd-GNPs exhibit markedly enhanced electrocatalytic performance during methanol electro-oxidation compared with monometallic Pt-GNP or commercially available Pt/C. Furthermore, the PtPd-GNP nanocatalysts also show greatly enhanced catalytic activity toward the oxygen reduction/evolution reaction in a lithium-oxygen (Li-O2) process, resulting in greatly improved cycling stability of a Li-O2 battery. [ABSTRACT FROM AUTHOR]

A new approach to the synthesis of fused 1,2,3-thiaselenazoles-rare five-membered heterocycles that contain two different chalcogens-from the corresponding 1,2,3-dithiazoles and SeO2 was accomplished by selective exchange of S and Se atoms. The fused carbo- and heterocyclic units were indene, naphthalenone, cyclohexadienone, cyclopentadiene, benzoannulene, and benzoxazine. The molecular structures of two of the thiaselenadiazole products and one of the dithiazole precursors were confirmed by single-crystal X-ray diffraction. The reaction is highly solvent selective; it only takes place in solvents that contain a C=O group (e.g., DMF or tetramethylurea). According to DFT calculations, the reaction is thermodynamically favorable. Based on the DFT calculations and 77Se NMR spectroscopy, two tentative mechanisms that feature isomeric transition states and intermediates are suggested for the reaction via ring-opening addition of SeO2 to the S−X dithiazole bond (X=N or S). The DFT-calculated first adiabatic electron affinities of the compounds were chalcogen independent and positive in all cases, which assumes formation of thermodynamically stable radical anions (RAs). These calculated RAs featured either normal or abnormal elongation of the S1−X2 (X=S or Se) bond relative to their neutral precursors and possessed π* or σ* SOMOs, respectively. [ABSTRACT FROM AUTHOR]

Synthesis of O-methylated glycolipids via direct stereoselective glycosidation whose sugar moieties are related to those in phenolic glycolipids (PGLs) is reported. Treatment of 2- O-methyl-rhamnosyl imidates with I2 and nBu4NOTf resulted in their activation under low temperature and provided the α-rhamnosides with excellent α-selectivity. nBu4NOTf enhanced the electorophilicity of iodine. This methodology improved the efficiency of the synthesis of both PGL-1 and PGL-tb1 sugars. The process involved the formation of 2- O-naphthylmethyl-α-rhamnoside and 2- O-methyl-α-fucoside. Sequential Suzuki-Miyaura coupling using synthetic glycosides, boracyclane, and aryl bromides provided glycolipids related to PGL sugars, and was accomplished with a one-pot process. Finally, we elucidated the immunosuppressive activities of all these synthetic compounds and found that a phenyl 3- O-α-rhamnosyl-2- O-methyl-α-rhamnoside possessing a 6-(2-naphthyl)hexyl group exhibited the strongest inhibitory effect. [ABSTRACT FROM AUTHOR]

The synthesis of the octadentate bispidine ligand bearing two picolinic acid pendant arms (H2bispa2), and its coordination chemistry with radionuclides relevant for nuclear medicine, namely indium(III) (111In), lutetium(III) (177Lu), and lanthanum(III) (as surrogate for 225Ac), are reported. The non-radioactive metal complexes of the N6O2-type bispa ligand were characterized by 1H and 13C NMR spectroscopy, elemental analysis, mass spectrometry and single-crystal X-ray analysis. Experimental structural data, computational analysis, complex stabilities determined by potentiometric titration, and 'radiostabilities' determined by competition studies in the presence of human serum reveal complex stabilities of H2bispa2 comparable to those of the macrocyclic 'gold standard' DOTA. After an incubation time of 1 day, 86 and 87 % of [177Lu(bispa2)]+ and [177Lu(DOTA)]−, respectively, remain intact. Importantly, unlike DOTA, H2bispa2 is radiolabeled quantitatively with 111InIII and 225AcIII under ambient conditions, which is an essential aspect when working with heat-sensitive antibodies as targeting vectors. In the case of 111InIII, room temperature radiolabeling of H2bispa2 yields molar activities as high as 70 MBq nmol−1 within 10 minutes. These are promising results for radiopharmaceutical applications of H2bispa2. [ABSTRACT FROM AUTHOR]

The controllable synthesis and structural tailoring of nanostructured metal-organic frameworks (MOFs) is of huge significance in boosting their potential for rechargeable batteries. We herein present the facile synthesis of cobalt-based ultrathin metal-organic framework nanosheets (referred to as 'u-CoTDA') by using 2,5-thiophenedicarboxylic (H2TDA) as the organic building block through a one-pot ultrasonic method for the first time. The obtained u-CoTDA exhibits high reversible capacity (790 mAh g−1 after 400 cycles at 1 A g−1) and excellent rate capability (694 mAh g−1 at 2 A g−1), which outperforms its bulk counterpart. Moreover, the detailed lithiation/delithiation processes of u-CoTDA were studied by the combination of Co K-edge X-ray absorption near edge structure (XANES), O K-edge soft X-ray spectroscopy (sXAS) and electron paramagnetic resonance (EPR) techniques, which demonstrate that both the CoII centers and organic ligands of u-CoTDA are involved in the reduction/oxidation processes. [ABSTRACT FROM AUTHOR]

The structure solution, prediction, and targeted synthesis of a family of embedded isoreticular zeolites (EIZs) with expanding structural complexity, denoted the RHO family, were reported recently. Here, the naming and building rules of body-centered cubic EIZs with the lta cage as the lattice point are presented. The rearrangement of a pair of pau and d8r cages between two lta cages and its repetitive insertion, combined with the strong reflections and fragment methods, allows the creation of three other new zeolite families, designated the HPO, RHO(b), and KFI families. Among them, the KFI family is found to be the only EIZ family, on the basis of the similarity of structure factor amplitudes and phases of strong reflections, that is, structural coding, within its family members. The structural credibility of this family is confirmed by both local interatomic distances and T−T−T angle analyses. The existence of tetragonal EIZ families is also demonstrated. The overall results provide useful insights into the prediction of unprecedented EIZ families. [ABSTRACT FROM AUTHOR]

The first stereoselective total synthesis of the natural product pyrronazol B, which contains a chlorinated pyrrole-oxazole-pyrone framework, has been achieved. Genome sequencing of the myxobacterial producer strain Nannocystis pusilla Ari7 led to the identification of the putative biosynthetic gene cluster. The proposed biosynthetic pathway was supported by feeding experiments with stable isotopes of three biosynthetic building blocks, namely l-proline, l-serine, and l-methionine. [ABSTRACT FROM AUTHOR]

Anhydrous hydroxide sulfates Ln2(OH)4SO4 (Ln=Eu-Lu, Y) were hydrothermally synthesized as a new family of layered rare earth metal hydroxides (LRHs). They crystallize in the monoclinic system (space group C2/ m) with structures built up by alternate stacking of interlayer SO42− and the two-dimensional host layer composed of tricapped [LnO9] trigonal prisms along the a axis. In distinct contrast to the recently discovered hydrated LRHs Ln2(OH)4SO4 ⋅2 H2O, which only exist for Ln=La-Dy, the host layers of the anhydrous phase are linked together by sharing edges instead of an O node of the SO42− tetrahedron. Rietveld refinement showed that the cell dimension tends to decrease for smaller Ln3+, while the axis angle ( β=98.78-100.31°) behaves oppositely. Comparative thermogravimetric/differential thermal analysis in air revealed that the dehydroxylation and desulfurization temperatures become gradually higher and lower, respectively, for smaller Ln3+, and thus the temperature range of Ln2O2SO4 existence is narrowed. The newly discovered Ln2(OH)4SO4, together with their hydrated counterparts, allow for the first time green synthesis of Ln2O2SO4 with water as the only exhaust for the full spectrum of lanthanides. Calcining Ln2(OH)4SO4 in H2 yielded phase-pure Ln2O2S for Eu and Gd and a mixture of Ln2O2S and Ln2O3 for the other Ln. The effects of the lanthanide contraction were clearly revealed, and photoluminescence was found for the anhydrous LRHs of Eu and Tb. [ABSTRACT FROM AUTHOR]

Four dibenzofuran-type host materials substituted with a carbazolylcarbazole moiety were synthesized to investigate the effect of substitution position on the material parameters and device performances of host materials. The carbazolylcarbazole moiety was substituted at the 1-, 2-, 3-, and 4-positions of dibenzofuran by F or Br for a comprehensive study of the positional effect of dibenzofuran-derived host materials. Systematic synthesis and comparison of the four host materials revealed that 1-, 2-, and 4-position modification was better than 3-position modification for high triplet energy and high external quantum efficiency. [ABSTRACT FROM AUTHOR]

A composite material, ZnO@MC, has been synthesized successfully by calcination using a one-dimensional zinc-based coordination polymer as the precursor. In ZnO@MC, ZnO particles with a size of about 5-8 nm are dispersed evenly in a mesoporous carbon matrix. Adsorption experiments at pH 6.8 with 2 mg ZnO@MC as adsorbent illustrated an adsorption efficiency of 92.3 % in 5 mL hemoglobin (Hb) solution with a concentration of 100 mg L−1. In contrast, the adsorption of bovine serum albumin can almost be ignored under the same conditions. The selectivity originates from a strong ZnII-histidine interaction between ZnO@MC and hemoglobin. The adsorption behavior of hemoglobin on ZnO@MC fits the Temkin model perfectly with a capacity as high as 11646 mg g−1. The hemoglobin adsorbed on the composite material can be eluted easily with sodium dodecyl sulfate stripping reagent with an extraction efficiency of 87.7 %. Circular dichroism spectra and protein activity studies suggest the structure and biological activity of hemoglobin is the same before and after the adsorption/desorption experiment. Finally, the ZnO@MC composite material was employed to extract hemoglobin from human whole blood without any pretreatment, and gave a very satisfactory result. [ABSTRACT FROM AUTHOR]

Carbonaceous materials are one of the most promising anode materials for sodium-ion batteries, because of their abundance, stability, and safe usage. However, the practical application of carbon materials is hindered by poor specific capacity and low initial Coulombic efficiency. The design of porous structure and doping with heteroatoms are two simple and effective methods to promote the sodium storage performance. Herein, the N, P co-doped porous carbon materials are fabricated using renewable and biodegradable gelatin as carbon and nitrogen resource, phosphoric acid as phosphorus precursor and polystyrene nanospheres as a template. The product can deliver a reversible capacity of 230 mA h g−1 at a current density of 0.2 A g−1, and even a high capacity of 113 mA h g−1 at 10 Ag−1. The enhanced sodium storage performance is attributed to the synergistic effect of the porosity and the dual-doping of nitrogen and phosphorus. [ABSTRACT FROM AUTHOR]