The photochemical deracemization of spiro[cyclopropane‐1,3'‐indolin]‐2'‐ones (spirocyclopropyl oxindoles) was studied. For the corresponding 2,2‐dichloro compound it was found that it is configurationally labile upon direct irradiation at λ = 350 nm and upon irradiation at λ = 405 nm in the presence of achiral thioxanthen‐9‐one as the sensitizer. The triplet 1,3‐diradical intermediate generated in the latter reaction was detected by transient absorption spectroscopy and its lifetime was determined...
Wed Aug 05, 2020 22:00
We hereby report the preparation of acyclic molecules featuring congested stereocenters in a 1,4‐relationship in only three catalytic steps from commercially available building blocks. Our approach involves a diastereoselective diboration of alkenyl cyclopropyl methanol derivatives followed by a regioselective exergonic ring fragmentation. As the starting materials can be prepared enantiomerically enriched and all substituents can be interconverted, this strategy allows a large variety of diversely...
Wed Aug 05, 2020 20:29
1‐Boraphenalenes, a class of boron‐doped polyaromatic hydrocarbons, were synthesized by nucleophilic diboration reaction of alkynes. Activation of diboron reagents with a highly basic sp 2 ‐carbanion results in very fast successive C–B bond formations to construct the boracycle. This methodology is characterized by high chemoselectivity, affording a wide variety of 1‐boraphenarenes with diverse polar substituents. The endocyclic boron can be arylated conveniently in one pot, and the peripheral...
Wed Aug 05, 2020 17:08
The practical applications of non‐aqueous lithium–oxygen batteries are impeded by large overpotentials and unsatisfactory cycling durability. Herein, we report that commonly encountered fatal problems can be efficiently solved by using a carbon‐ and binder‐free electrode of titanium coated with TiO 2 nanotube arrays (TNAs) and gold nanoparticles (AuNPs). Ultraviolet irradiation of the TNAs generates positively charged holes, which efficiently decompose Li 2 O 2 and Li2CO3 during recharging...
Wed Aug 05, 2020 17:07
On‐surface synthesis is emerging as a highly rational bottom‐up methodology for the synthesis of molecular structures that are unattainable or complex to obtain by wet chemistry. Here, oligomers of meta‐ polyaniline, a known ferromagnetic polymer, were synthesized from para ‐aminophenol building‐blocks via an unexpected and highly specific on‐surface formal 1,4 Michael‐type addition at the meta position, driven by the reduction of the aminophenol molecule. We rationalize this dehydrogenation...
Wed Aug 05, 2020 17:06
Photo‐mediation offers unparalleled spatiotemporal control over controlled radical polymerizations (CRP). Photo‐induced electron/energy transfer reversible addition‐fragmentation chain transfer (PET‐RAFT) polymerization is particularly versatile due to its oxygen tolerance and wide range of compatible photocatalysts. In recent years, broadband‐ and near‐infrared (NIR)‐mediated polymerizations have been of particular interest due to their potential for solar‐driven chemistry and biomedical applications....
Wed Aug 05, 2020 17:05
We report the rearrangement of sulfur‐containing aldehydes using a sulfonium enamine intermediate as a formylcarbene mimetic. This is an enantioselective, organocatalytic [2,3]‐sigmatropic rearrangement enabling chiral cyclic sulfides bearing an α‐quaternary chiral center to be prepared in high optical purity. The enantioselectivity is controlled with a cooperative organocatalyst pair consisting of a chiral amine and a chiral phosphoric acid (CPA). The synthetic versatility of this method is demonstrated...
Wed Aug 05, 2020 17:02
Alkenylphosphine oxides have a wide spectrum of practical applications. However, high chemo‐, regio‐ and enantio‐controlled construction of this structural motif still constitutes a significant synthetic challenge. Here we show an efficient strategy that can be realized via the palladium/Xiao‐Phos catalytic system, which lead to highly regioselective formation of the anti‐Markovnikov adducts by addition of a secondary phosphine oxide to an alkyne. Diverse (hetero)aryl, alkyl alkynes and both terminal...
Wed Aug 05, 2020 16:01
A newly introduced Na–B bond in NaBH 3 – has been a challenge for chemical bonding community. Here, a series of MBH 3 – (M = Li, Na, K) and NaB(CN) 3 – are studied within the context of quantum chemical topology approaches. The analyses suggest that M–B interaction cannot be classified as an ordinary covalent, dative, even a simple ionic interaction. The interactions are controlled by coulombic forces between metals and the substituents on the boron, e.g. H or CN, more than the direct M–B...
Wed Aug 05, 2020 14:34
Phosphorescent dopants are promising candidates in organic light‐emitting diodes (OLEDs). While it has been established that the out‐coupling efficiency and overall performances of vacuum‐deposited OLEDs can be significantly improved by a horizontal orientation of the dopants, no horizontally‐oriented gold(III) complexes have been reported to date. Here, we have successfully generated a novel class of tetradentate gold(III) C^C^N^N complexes with a preferential horizontal orientation through a one‐pot...
Wed Aug 05, 2020 11:21
19F NMR‐based fragment screening is an effective approach in pharmaceutical research to explore the chemical space for specific target–ligand interactions. In their Research Article (DOI: https://doi.org/10.1002/anie.20200246310.1002/anie.202002463), A. Lingel, A. O. Frank et al. report on the development of NMR pulses that cover the entire drug‐like fluorine chemical shift range in a single experiment. The new method allows for the efficient assembly of diverse fragment libraries that can be screened...
Tue Aug 04, 2020 22:58
Dynamic covalent chemistry can be performed on the surface of living cells. In their Communication (DOI: https://doi.org/10.1002/anie.20200474510.1002/anie.202004745), I. Alfonso et al. describe the Live‐Cell‐Templated Dynamic Combinatorial Chemistry approach for the identification of a strong binder to the glycosaminoglycans of the extracellular matrix of human lung adenocarcinoma cells. Cover image by M. Eugenio Vázquez, @ChemBioUSC.
Tue Aug 04, 2020 22:58
The supertetrahedral cluster [Au6(Ge3As)(Ge2As2)3]3− is obtained from [(PPh3)AuMe] and the binary Zintl anion (Ge2As2)2−, which readily undergoes an in situ atom exchange in solution to form (GeAs3)− and (Ge3As)3−. The latter is required to form the product, which comprises the largest number of Au atoms relative to main group (semi)metal atoms in such clusters. Abstract The Zintl anion (Ge2As2)2− represents an isostructural and isoelectronic binary counterpart of yellow arsenic, yet without...
Tue Aug 04, 2020 22:58
Heterogeneous CO2 reduction with a novel planar and conjugated N4‐macrocyclic metal complex of Co(II)CPY/CNT was investigated. Systematic investigation in aqueous electrolyte shows it has high activity and outperforms most of metal complexes reported so far. Abstract Metal complexes have been widely investigated as promising electrocatalysts for CO2 reduction. Most of the current research efforts focus mainly on ligands based on pyrrole subunits, and the reported activities are still far...
Tue Aug 04, 2020 22:58
Rabies virus‐inspired metal–organic frameworks (MILB@LR) for targeted imaging and chemotherapy of glioma are demonstrated by Z. Wang et al. in their Research Article (DOI: https://doi.org/10.1002/anie.20200747410.1002/anie.202007474). Inspired by the extraordinary capability of rabies virus (RABV) to enter the central nervous system, MILB@LR were designed to closely mimick both the bullet‐shape structure and surface functions of natural RABV. MILB@LR exhibit significantly enhanced glioma targeting...
Tue Aug 04, 2020 22:57
Earth‐abundant/biocompatible metal catalysts for asymmetric cis‐dihydroxylation (AD) of trisubstituted alkenes, in which OsO4‐based catalysts have been widely used, are highly appealing. In their Research Article (DOI: https://doi.org/10.1002/anie.20200286610.1002/anie.202002866), C.‐M. Che and co‐workers describe a cis‐FeII(chiral N4 ligand)/H2O2 method which is an alternative/complement to the OsO4‐based method and converts various trisubstituted alkenes to cis‐diols in synthetically useful yields...
Tue Aug 04, 2020 22:56
Solid‐state lithium metal batteries (LMBs) are an emerging field of energy storage. The inherent benefits of solid electrolytes, however, are offset by difficulties at the lithium|electrolyte interface. In this study, the often‐overlooked wetting phenomena of widely used polymeric electrolytes (PEs) are discussed and the strong influence of the topography of the lithium metal (Li) surface and the viscoelastic properties of the PEs on the Li|PEs interface are presented. Abstract Li metal...
Tue Aug 04, 2020 22:56
The cage type molecule S6N2O15 is not only a new sulfur nitride oxide, but also the anhydride of the rarely seen nitrido‐tris‐sulfuric acid. Interestingly, the unique compound is obtained in high yields from reactions of SO3 with P3N3Cl6. Abstract The reaction of hexachlorophosphazene, P3N3Cl6, with SO3 leads to the new sulfur nitride oxide S6N2O15. The compound displays an extraordinarily low nitrogen content and exhibits a bicyclic cage structure according to the formulation N{S(O)2O(O)2S}3N,...
Tue Aug 04, 2020 22:54
Low‐energy electrons make a choice : Upon the attachment of a low‐energy electron to the potential radiosensitizer compound tirapazamine in the gas phase, dissociation of the OH radical is by far the most abundant reaction obtained. Other dissociation channels as well as the metastable parent anion formed upon roaming of OH are computationally predicted. Abstract Tirapazamine (TPZ) has been tested in clinical trials on radio‐chemotherapy due to its potential highly selective toxicity towards...
Tue Aug 04, 2020 22:54
CdTeSe alloy magic‐size clusters have been synthesized, but the formation mechanism of their precursor compounds (which can transform to CdTeSe magic‐size clusters) was unknown. As reported by X. Chen, K. Yu and co‐workers in their Research Article (DOI: https://doi.org/10.1002/anie.20200564310.1002/anie.202005643), CdTeSe precursor compounds were formed through a substitution reaction: CdTe precursor compound + CdSe monomer/fragment → CdTeSe precursor compound + CdTe monomer/fragment.
Tue Aug 04, 2020 22:54
An ultrastable silver nanocluster was synthesized by K. Yamaguchi, K. Suzuki et al. in their Communication (DOI: https://doi.org/10.1002/anie.20200840210.1002/anie.202008402) by using lacunary polyoxometalates. In the cover picture, the green polydedra represent lacunary polyoxometalates and the light gray spheres silver atoms. While small silver nanoclusters are typically highly fragile, the small Ag7 nanocluster shows unprecedented stability when surrounded by a triangular hollow polyoxometalate...
Tue Aug 04, 2020 22:54
The self‐assembling features of N‐annulated perylene bisimides (PBIs) 1 and 2 are reported by E. Ortí, L. Sánchez et al. in their Research Article (DOI: https://doi.org/10.1002/anie.20200583710.1002/anie.202005837). The stability of the aggregates of diester 1 substantiates the significance of van‐der‐Waals and dipole–dipole electrostatic interactions in the construction of stable supramolecular assemblies. The incorporation of amide functional groups in 2 results in a stimulating pathway differentiation...
Tue Aug 04, 2020 22:54
Dissociative adsorption of hydrogen is central to the development of approaches that predict gas‐surface reactions. Here, we determine absolute reactivities for dissociation at low coordinated Pt sites. Two curved Pt(111) single crystal surfaces allow us to probe either straight or highly kinked step edges with molecules impinging at a low impact energy. A simple model extracts the average reactivity of inner and outer kink atoms, which is compared to the reactivity of straight A‐...
Tue Aug 04, 2020 22:00
Catalytic difunctionalization of alkenes is a powerful and efficient tool to synthesize complex molecules from simple starting materials. Remote difunctionalization of unactivated alkenes is more challenging but highly attractive tactic to install two functional groups across long distances. Herein, we report the first remote difunctionalization of alkenes with CO 2 . This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids, such as non‐natural...
Tue Aug 04, 2020 20:05
Ru/Al 2 O 3 is a highly stable, but less active catalyst for methanation reactions. Here we report an effective approach to significantly improve its performance in the methanation of CO 2 /H 2 mixtures. Highly active and stable Ru/γ‐Al 2 O 3 catalysts were prepared by high‐temperature treatment in the reductive reaction gas. Operando / in situ spectroscopy and STEM imaging reveals that the strongly improved activity, by factors of 5 and 14 for CO and CO 2 methanation, goes along...
Tue Aug 04, 2020 20:05
HER2‐positive breast cancer represents aggressive subtype typical of poor response to standard chemotherapy. To design an anticancer drug selective for HER2 expressing breast cancer, the new Pt(IV) prodrug with axial oleate and cinnamate ligands was synthesized. We demonstrate its superior antiproliferative activity in monolayer and 3D spheroid models; the antiproliferative efficiency increases gradually with increasing expression of HER2. The results also suggest that the released Pt(II) compound...
Tue Aug 04, 2020 20:02
Enzyme powered micro/nanomotors have great potential applications in various areas. To efficiently reach those applications, it is necessary to understand the fundamental aspects affecting the motion dynamics. Herein, we explored the impact of enzyme orientation on the performance of lipase‐powered nanomotors by tuning the lipase immobilization strategies. The influence of the lipase orientation and lid conformation on substrate binding and catalysis was analyzed via MD simulations. Besides, the...
Tue Aug 04, 2020 18:29
Biaryls are extremely important structural motifs in natural products, biologically active components and pharmaceuticals. Selective synthesis of biaryls by distinguishing the subtle reactivity difference of distal arene‐C−H bonds are significantly challenging. However, prudent orchestration of suitable directing group to mitigate the required geometrical orientation for site selective functionalizations can lead to a handful tool to construct the molecular complexity. Herein we embarked on exploring...
Tue Aug 04, 2020 17:03
In recent years, several tetracyanobuta‐1,3‐diene (TCBD) conjugates have been prepared by linking the tetracyano unit to various electroactive moieties. These push‐pull conjugates, besides showing interesting physicochemical properties, are axially chiral, a feature arising from the restricted rotation around the butadiene’s central bond. Yet, only in a few cases, enantiomers’ separation and isolation have been successfully achieved, owing to the configurational lability of the corresponding enantiopure...
Tue Aug 04, 2020 17:02
The first asymmetric total synthesis of cephanolide A, a complex hexacyclic C18 dinorditerpenoid from cephalotaxus sinensis, was achieved. The synthesis features a convergent strategy, which provides a flexible approach to prepare the biogenetically cephalotaxus diterpenoids and structurally related derivatives for biological studies. A mild intramolecular Prins cyclization was developed to construct the central hexahydrofluorenol skeleton (A−B−C ring) which relies on the originally proposed hydroacylation...
Tue Aug 04, 2020 15:58
Binders of Langerin could target vaccines to Langerhans cells for improved therapeutic effect. As Langerin has only low affinity for monovalent glycan ligands, highly multivalent presentation has previously been key for targeting. Aiming to reduce the amount of ligands required, we rationally designed molecularly defined high affinity binders based on the precise display of glycomimetic ligands (Glc2NTs) on DNA‐PNA scaffolds. Rather than mimicking Langerin’s homotrimeric structure with a C3‐symmetrical...
Tue Aug 04, 2020 15:24
A dual‐site catalyst coordinated with a stable bridge‐O modifier has been designed and synthesized, tailoring the d‐orbital electronic structure of Fe and weakening the binding energy of oxygen reduction reaction (ORR) intermediates. Thus, the catalytic activity climbs upward along the left side of the ORR volcano plot. Abstract The applications of the most promising Fe—N–C catalysts are prohibited by their limited intrinsic activities. Manipulating the Fe energy level through anchoring...
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