• Issue

    Chemistry – A European Journal: Volume 26, Issue 69

    16145-16562
    December 9, 2020

Cover Pictures

Free Access

Front Cover: Atomically Precise Alloy Nanoclusters (Chem. Eur. J. 69/2020)

  • Pages: 16145
  • First Published: 27 October 2020
Description unavailable

Research on alloy nanoclusters (NCs) has become a hot topic in the study of metal NCs and the number of publications on alloy NCs has increased explosively in recent years. This review summarizes the reported chemical composition, geometrical structure, electronic structure, and physical and chemical properties of alloy NCs nanoclusters to date. This review is expected to help researchers understand the characteristics of alloy NCs and lead to clear design guidelines to develop new alloy NCs. More information can be found in the Review by Y. Negishi et al. on page 16150.

Free Access

Cover Feature: Electron-Deficient Imidazolium Substituted Cp Ligands and their Ru Complexes (Chem. Eur. J. 69/2020)

  • Pages: 16146
  • First Published: 12 October 2020
Description unavailable

Electron-poor cyclopentadienide ligands based on neutral, cationic and dicationic imidazolium Cp ylides were prepared. The donating properties of these colorful compounds were analyzed by their oxidation potentials as well as that of their respective ruthenocene complexes. Each substitution by an imidazolium moiety increases the oxidation potential of about 500 mV. In addition, fixing the imidazolium moieties in the Cp plane by annellation also induces a withdrawing effect. More information can be found in the Full Paper by D. Kunz et al. on page 16291.

Free Access

Cover Feature: Synthesis of Bio-Inspired Guanine Microplatelets: Morphological and Crystallographic Control (Chem. Eur. J. 69/2020)

  • Pages: 16147
  • First Published: 12 October 2020
Description unavailable

Guanine crystals are widely found in a variety of organisms for achieving diverse optical effects, including the silvery reflection from the tropical fish shown in the background. This work reports a synthetic method to fabricate guanine microplatelets with facile control in morphological and crystallographic characteristics. These bio-inspired guanine crystals exhibit (100) exposing planes in β-phase, similar to biological guanine crystals, which results in pearly lusters due to their high reflectivity when dispersed in water. More information can be found in the Communication by L. Li, L. Qi, Y. Ma, et al. on page 16228.

Free Access

Cover Feature: Supramolecular Sensor for Astringent Procyanidin C1: Fluorescent Artificial Tongue for Wine Components (Chem. Eur. J. 69/2020)

  • Pages: 16148
  • First Published: 12 October 2020
Description unavailable

Pyridinium boronic acid-attached polythiophene derivatives (depicted as grape leaves in the cover image) as chemosensors for the comprehensive taste evaluation of wine are reported in this work. The fluorescence chemosensor array (barrels in the cover image) exhibited turn-off responses to the major types of taste components of wine. Furthermore, quantitative analysis for the wine components was successfully carried out in a real red wine. This study proposes a unique “chemosommelier” system for the accurate prediction of taste. More information can be found in the Communication by T. Minami et al. on page 16236.

Frontispiece

Free Access

Frontispiece: Atomically Precise Alloy Nanoclusters

  • First Published: 09 December 2020
Description unavailable

Alloy nanoclusters (NCs) have become a hot topic in the study of metal NCs and the number of publications on alloy NCs has increased explosively in recent years. Such publications have provided much insight into the effects of alloying on the electronic structure and function of alloy NCs. Here, the obtained knowledge for AunxMx(SR)m, AgnxMx(SR)m, AunxMx(PR3)l(SR)m, and AgnxMx(PR3)l(SR)m (Au=gold, Ag=silver, M=heteroatom, PR3=phosphine, and SR=thiolate) NCs is summarized. For more details see the Review by Y. Negishi et al. on page 16150.

Free Access

Frontispiece: Conformation Control of Conjugated Polymers

  • First Published: 09 December 2020
Description unavailable

The electronic properties of conjugated polymers are strongly affected by the conformation of the polymer backbone. A rigid coplanar conformation could significantly improve the intrachain and interchain charge transport. Three types of conjugated polymers with rigid coplanar conformations are introduced. Complete conformation control strategies of conjugated polymers are summarized in this Minireview by J. Pei et al. on page 16194.

Free Access

Frontispiece: Insights into the Mechanism of Gold(I) Oxidation with Aryldiazonium Salts

  • First Published: 09 December 2020
Description unavailable

Aryldiazonium salts have emerged as efficient electrophiles for the oxidative addition of gold. In this minireview we enclose the mechanistic evidences gained so far by different authors concerning the mechanism. It is of common acceptance that aryladicals are crucial intermediates in these processes. Interestingly, it has been manifested that there are various successful ways to activate aryldiazonium salts for the generation of the desired arylgold(III) species. Generally speaking, these methods can be encompassed in: photoredox activation, photo activation and chemical activation. For more information see the Minireview by I. Medina-Mercado and S. Porcel on page 16206. The frontispiece graphic was designed by Hortensia Segura Silva.

Free Access

Frontispiece: Transformation of COUPY Fluorophores into a Novel Class of Visible-Light-Cleavable Photolabile Protecting Groups

  • First Published: 09 December 2020
Description unavailable

A new class of visible-light-sensitive photolabile protecting groups based on low-molecular weight COUPY fluorophores, which expand the current photochemical toolbox, is described. Besides being efficiently photoactivated with yellow and red light under physiological-like conditions, COUPY photocages exhibit excellent cellular uptake and accumulate selectively in mitochondria, opening the door to the delivery of caged analogues of biologically active compounds into these organelles. For more details see the Communication by V. Marchán et al. on page 16222.

Cover Profile

Free Access

Atomically Precise Alloy Nanoclusters

  • Pages: 16149
  • First Published: 29 October 2020
Description unavailable

In this review, we summarize the chemical composition, geometrical structure, electronic structure, and physical and chemical properties of the reported metal nanoclusters (NCs). This review is expected to help researchers understand the characteristics of alloy NCs and lead to clear design guidelines to develop new alloy NCs with intended functions.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 16150 ff. (DOI: 10.1002/chem.202001877).

Reviews

Nanostructures

Atomically Precise Alloy Nanoclusters

  • Pages: 16150-16193
  • First Published: 26 May 2020
Description unavailable

Various electronic and geometrical structures and functions can be obtained by alloying metal nanoclusters (NCs). This review summarizes the chemical composition, geometrical structure, electronic structure, and physical and chemical properties of alloy NCs reported to date. This summary will help researchers to understand the characteristics of alloy NCs, which should lead to design guidelines to develop alloy NCs with intended functions.

Minireviews

Polymers

Conformation Control of Conjugated Polymers

  • Pages: 16194-16205
  • First Published: 28 April 2020
Description unavailable

Under control: Conformation control strategies from the molecular level for conjugated polymers in the past several decades are summarized, with a focus on their influence on device performance and challenges in synthesis, characterization and subsequent processing.

Catalysis | Reviews Showcase

Insights into the Mechanism of Gold(I) Oxidation with Aryldiazonium Salts

  • Pages: 16206-16221
  • First Published: 31 May 2020
Description unavailable

A dose of salt: Aryldiazonium salts are able to oxidize gold(I) in combination with a photocatalyst and light irradiation or simply by irradiation, heating, or the addition of certain bases and/or nucleophiles. The specific steps underlying the oxidation depend upon the activation mode of the aryldiazonium salt.

Communications

Photochemistry | Hot Paper

Transformation of COUPY Fluorophores into a Novel Class of Visible-Light-Cleavable Photolabile Protecting Groups

  • Pages: 16222-16227
  • First Published: 12 June 2020
Description unavailable

The transformation of coumarin-based COUPY fluorophores into a new class of visible light-sensitive photolabile protecting groups, which expand the current photochemical toolbox, is reported. Besides exhibiting an excellent cellular uptake, COUPY photocages accumulate selectively in mitochondria, thereby offering the possibility of delivering biologically active compounds within this organelle in a selective manner.

Crystal Growth | Hot Paper

Synthesis of Bio-Inspired Guanine Microplatelets: Morphological and Crystallographic Control

  • Pages: 16228-16235
  • First Published: 04 September 2020
Description unavailable

Guanine crystals are widely observed in a variety of organisms for achieving diverse optical effects, such as broadband reflection, photonic coloration, and vision. Chen et al. report a facile synthesis method to fabricate guanine microplatelets with controlled morphological and crystallographic characteristics similar to biological guanine crystals (see figure).

Sensors

Supramolecular Sensor for Astringent Procyanidin C1: Fluorescent Artificial Tongue for Wine Components

  • Pages: 16236-16240
  • First Published: 07 July 2020
Description unavailable

Fluorescent polythiophene derivatives for comprehensive taste evaluation of wine are reported. In particular, the first detection of astringent procyanidin C1 by chemosensors has been achieved at a practical concentration range in real wine. Furthermore, the regression analysis for the astringent was successfully carried out in real red wine. Our strategy leads to “the chemosommelier” for the accurate prediction of taste.

Pseudo-Natural Products

Open Access

Syntheses of Thailandepsin B Pseudo-Natural Products: Access to New Highly Potent HDAC Inhibitors via Late-Stage Modification

  • Pages: 16241-16245
  • First Published: 29 July 2020
Description unavailable

New thailandepsin B pseudo-natural products have been prepared applying rhodium-catalyzed hydrooxycarbonylation. This strategy gives access to the asymmetric branched allylic ester moiety in a highly diastereoselective manner. Varying warheads have been introduced via late stage modification. The newly developed compounds are extremely potent and selective HDAC inhibitors

Transition-Metal Catalysis | Hot Paper

Electrophilicity Scale of Activated Amides: 17O NMR and 15N NMR Chemical Shifts of Acyclic Twisted Amides in N−C(O) Cross-Coupling

  • Pages: 16246-16250
  • First Published: 15 July 2020
Description unavailable

An electrophilicity scale is herein reported by exploiting 17O NMR and 15N NMR chemical shifts of acyclic twisted and destabilized acyclic amides that have recently received major attention as precursors in N-C(O) cross-coupling and electrophilic activation. Most crucially, acyclic twisted amides feature electrophilicity of the carbonyl group that ranges between that of acid anhydrides and acid chlorides.

Organometallic Chemistry | Hot Paper

Open Access

NHCs as Neutral Donors towards Polyphosphorus Complexes

  • Pages: 16251-16255
  • First Published: 03 August 2020
Description unavailable

Access to polyphosphorus complexes: A dynamic behavior between [Cp*Fe(η5-P5)] and NHCs in solution is reported. NMR investigations showed a bond formation and bond breaking process between [Cp*Fe(η5-P5)] and the NHCs. Despite this dynamic behavior in solution, adducts of [Cp*Fe(η5-P5)] and NHCs can be isolated as solids. The tantalum complex [Cp′′Ta(CO)24-P4)] reacts with the NHC via a phosphorus atom abstraction and a ring contraction to a novel anionic cyclo-P3 complex.

Biosensors

Improvement of Molecular Diagnosis Using Domain-Level Single-Nucleotide Variants by Eliminating Unexpected Secondary Structures

  • Pages: 16256-16260
  • First Published: 15 September 2020
Description unavailable

By eliminating the unexpected secondary structure of oligonucleotides, this work reports the realization of domain-level SNV molecular diagnoses and identifies four highly homologous strands.

Deoxyfluorination | Hot Paper

Tertiary-Amine-Initiated Synthesis of Acyl Fluorides from Carboxylic Acids and CF3SO2OCF3

  • Pages: 16261-16265
  • First Published: 20 September 2020
Description unavailable

Amine-triggered deoxyfluorination of carboxylic acids with CF3SO2OCF3 is described. The reaction proceeds rapidly at room temperature under metal-free conditions to form various acyl fluorides in up to 97 % yield. This protocol represents the first utilization of trifluoromethyl trifluoromethanesulfonate as a convenient and efficient fluorination reagent.

Organic Chemistry | Hot Paper

Brønsted Acid-Catalyzed Enantioselective Cycloisomerization of Arylalkynes

  • Pages: 16266-16271
  • First Published: 25 September 2020
Description unavailable

Chiral N-triflyl phosphoramides catalyze the asymmetric carbocyclization of alkynyl aryl substrates. The introduction of a 2-naphtolyl substituent on the alkyne enables the chemo- and regioselective protonation of alkynes and delivers atropisomeric phenanthrenes and dihydronaphtalenes enantioselectively.

Metal–Organic Frameworks

“Orthogonal-Twisted-Arm” Ligands for The Construction of Metal–Organic Frameworks (MOFs): New Topology and Catalytic Reactivity

  • Pages: 16272-16276
  • First Published: 04 October 2020
Description unavailable

New topology: Extended tetratopic benzoic acid ligands with “orthogonal-twisted-arms” conformations were designed and synthesized for the construction of new MOF structures (OTA-MOF). X-ray single crystal structures were successfully obtained, demonstrating the formation of a new topology (4,4,4-c). The OTA2-MOF-Cu gave moderate stability in organic solvents and good gas-sorption ability towards CO2.

Synthetic Methods

Open Access

Copper-Catalyzed Addition of Grignard Reagents to in situ Generated Indole-Derived Vinylogous Imines

  • Pages: 16277-16280
  • First Published: 22 September 2020
Description unavailable

Asymmetric addition: The first protocol for catalytic asymmetric conjugate addition of Grignard reagents to various vinylogous imines, generated in situ from sulfonyl indoles have been developed by using catalyst system based on copper(I) salt and chiral phosphoramidite ligand.

Enzyme Engineering

Open Access

Asymmetric Biocatalytic Synthesis of 1-Aryltetrahydro-β-carbolines Enabled by “Substrate Walking”

  • Pages: 16281-16285
  • First Published: 05 October 2020
Description unavailable

Walking to new frontiers: Taking the challenge that not a single biocatalyst was available for the Pictet–Spengler reaction with benzaldehyde derivatives, modern tools of enzyme engineering were applied in a joined forces approach. Thus, a catalyst displaying the desired activity was created, giving optically enriched products with up to 99 % ee.

Coordination Polymers

One-Step Synthesis of Spin Crossover Nanoparticles Using Flow Chemistry and Supercritical CO2

  • Pages: 16286-16290
  • First Published: 10 July 2020
Description unavailable

One small step: An innovative and robust template-free continuous process allows the synthesis of nanoparticles of a switchable coordination polymer, including the use of supercritical CO2 and aiming at both quenching the particle growth and drying the powder.

Full Papers

Organometallic Chemistry | Hot Paper

Open Access

Electron-Deficient Imidazolium Substituted Cp Ligands and their Ru Complexes

  • Pages: 16291-16305
  • First Published: 30 September 2020
Description unavailable

Ligand design and application: The synthesis of electron-poor imidazolium substituted Cp-ylides is presented. Their electronic properties are elucidated based on NMR spectroscopy, DFT and reactivity studies. The first η5-Cp coordination of electron-poor cationic ylides is confirmed by X-ray structure analyses and an equilibrium for the coordination of a Cp ligand is observed. Electrochemical investigations of the ligands and of the ruthenocenes quantify the decreasing donor properties with increasing number of imidazolium substituents.

Schiff Bases

Triarylborane-Appended Anils and Boranils: Solid-State Emission, Mechanofluorochromism, and Phosphorescence

  • Pages: 16306-16317
  • First Published: 24 June 2020
Description unavailable

On the TAB: The effect of incorporating electron-deficient triarylboron (TAB) units on the optical properties of anils and boranils was rationalized for a series of TAB-coupled anils and boranils. The nature of the spacer and the position of the TAB affect the properties of these compounds. All the compounds are emissive in the solid state and boranils exhibit stimuli-responsive mechanofluorochromism and low-temperature phosphorescence.

Medicinal Chemistry | Hot Paper

MUC1 Aptamer-Capped Mesoporous Silica Nanoparticles for Navitoclax Resistance Overcoming in Triple-Negative Breast Cancer

  • Pages: 16318-16327
  • First Published: 31 July 2020
Description unavailable

Mesoporous silica nanoparticles loaded with navitoclax and the Mcl-1 inhibitor S63845, and capped with a MUC1-targeting aptamer are presented as effective nanodevices for navitoclax resistance overcoming targeted to triple-negative breast cancer cell lines.

Supercapacitors

Insight into the Effect of ZIF-8 Particle Size on the Performance in Nanocarbon-Based Supercapacitors

  • Pages: 16328-16337
  • First Published: 14 July 2020
Description unavailable

Make to measure: A series of ZIF-8 has been synthesized and carbonized to prepare porous carbons for use in supercapacitors. An optimal particle size of ZIF-8 for the best capacitive performance was obtained. This can serve as a relative normative reference to guide ZIF-8-based supercapacitors to achieve superior performance in the future.

Antimony(III) Complexes

Structures and Chemical Bonding in Antimony(III) Bromide Complexes with Pyridine

  • Pages: 16338-16348
  • First Published: 16 July 2020
Description unavailable

Six new SbBr3-Py crystalline complexes were obtained and structurally characterized. In all complexes Sb atoms display pseudo-octahedral coordination geometry where the coordination number of Sb center are increased to six due to pnictogen bonds. Non-covalence criterion NCC is proposed for the qualitative estimation of the bonding situation.

Medicinal Chemistry

Open Access

Functional Hybrid Molecules for the Visualization of Cancer: PESIN-Homodimers Combined with Multimodal Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging: Suited for Tracking of GRPR-Positive Malignant Tissue

  • Pages: 16349-16356
  • First Published: 03 July 2020
Description unavailable

Multimodal imaging: Different PESIN-homodimers, suited for positron emission tomography and optical imaging, were synthesized. Special focus was set on the influence of different dyes on biomedical-related properties.

Synthetic Methods | Hot Paper

Open Access

Suzuki–Miyaura Cross-Coupling of Bromotryptophan Derivatives at Ambient Temperature

  • Pages: 16357-16364
  • First Published: 08 July 2020
Description unavailable

Gentle conditions: Ligand-free solvent-stabilised Pd-nanoparticles serve as a highly efficient catalyst at ambient temperature for a sustainable and biocompatible Suzuki–Miyaura cross-coupling between aryl bromides and boronic acids under mild, aerobic and aqueous conditions.

Catalysis

Open Access

Photocatalytic CO2 Reductions Catalyzed by meso-(1,10-Phenanthrolin-2-yl)-Porphyrins Having a Rhenium(I) Tricarbonyl Complex

  • Pages: 16365-16373
  • First Published: 29 July 2020
Description unavailable

The Zn porphyrin and Re complex dyad acted as a good photocatalyst in photocatalytic CO2 reduction using both triethylamine and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH) as an electron donor. The central Zn ion of the porphyrin played an important role in high durability. The effect of acids on the photocatalytic CO2 reduction was investigated with BIH, showing proper weak Brønsted acids enhanced the CO2 reduction.

Photocatalysis

Open Access

Versatile Visible-Light-Driven Synthesis of Asymmetrical Phosphines and Phosphonium Salts

  • Pages: 16374-16382
  • First Published: 02 June 2020
Description unavailable

Driven by light: A mild and facile photoredox approach towards asymmetrically substituted phosphines and phosphonium salts is reported. Blue-light irradiation of mono- and diphenylphosphine with various aryl and alkyl iodides, diisopropylethylamine (DIPEA), and the organic photocatalyst 3DPAFIPN affords the desired products in good-to-excellent yields. In addition, the same method transforms white phosphorus (P4) directly into symmetrical aryl phosphines and phosphonium salts.

Organic Light-Emitting Diodes

Asymmetric Host Molecule Bearing Pyridine Core for Highly Efficient Blue Thermally Activated Delayed Fluorescence OLEDs

  • Pages: 16383-16391
  • First Published: 19 July 2020
Description unavailable

Bipolar host: A high efficiency and long lifetime of blue TADF-OLEDs is achieved by synthesizing pCzBzbCz and pCzPybCz host materials. The pCzPybCz-based devices exhibit a high EQE of 22.7 % and an operational lifetime of 24 h (LT90) at an initial luminance of 1000 cd m−2.

Nanostructures

Hierarchical Carbon Nanowire/Ni@MnO2 Nanocomposites for High-Performance Asymmetric Supercapacitors

  • Pages: 16392-16401
  • First Published: 28 August 2020
Description unavailable

Supercapacitive nanoarchitectures: A rationally designed 3D hierarchical carbon cloth/nitrogen-doped carbon nanowires/Ni@MnO2 (CC/N-CNWs/Ni@MnO2) nanocomposite was prepared by electrodeposition and used as a supercapacitor cathode exhibiting high surface area, outstanding electrical conductivity, and excellent performance in supercapacitors.

Microporous Materials

New Supercage Metal–Organic Framework Based on Allopurinol Ligands Showing Acetylene Storage and Separation

  • Pages: 16402-16407
  • First Published: 16 July 2020
Description unavailable

A rare adsorptive material based on three types of MOF cages was successfully constructed through the medicinal molecule allopurinol and a dicarboxylate linker, displaying selective adsorption for C2H2 over CO2 and C2H2 over CH4. The multiple binding sites in the frameworks for guest molecules were also confirmed by simulations.

Total Synthesis | Hot Paper

Total Synthesis of Mallotusinin

  • Pages: 16408-16421
  • First Published: 02 July 2020
Description unavailable

Synthesis of mallotusinin: The total synthesis of mallotusinin via the second-generation synthesis of corilagin is described. The key steps are as follows: 1) oxidative phenol coupling of 1,2,4-orthoacetyl-3,6-di-(4-O-benzylgalloyl)-α-d-glucopyranose; 2) orthoester cleavage along with thioglycosylation followed by β-selective glycosyl esterification; and 3) two-step bislactonization to construct a 2,4-O-tetrahydroxydibenzofuranoyl bridge on corilagin.

Donor–Acceptor Systems | Hot Paper

Triphenylamine/Tetracyanobutadiene-Based π-Conjugated Push–Pull Molecules End-Capped with Arene Platforms: Synthesis, Photophysics, and Photovoltaic Response

  • Pages: 16422-16433
  • First Published: 23 July 2020
Description unavailable

D-π-A push–pull molecules based on triphenylamine and 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) functionalized with terminal arene units strongly absorb in the visible spectrum, but they do not show detectable photoluminescence in solution in agreement with their very short singlet excited state deactivation time. The latter significantly increases in the solid state making TCBD derivatives potential candidates for photovoltaic applications.

Physical Chemistry

Noncovalent Intermolecular Interaction in Cofacially Stacked 24π Antiaromatic Hexaphyrin Dimer

  • Pages: 16434-16440
  • First Published: 17 June 2020
Description unavailable

Unprecedented phenomenon of dimerization via π–π interactions between two antiaromatic π-conjugated molecules was precisely examined through a wide selection of spectroscopic techniques, as well as theoretical calculations with controlling the interplanar distance.

Chalcogens

Open Access

Chiral Chalcogenyl-Substituted Naphthyl- and Acenaphthyl-Silanes and Their Cations

  • Pages: 16441-16449
  • First Published: 06 July 2020
Description unavailable

The Corey reaction of acenaphthyl- and naphthyl-based chiral silanes allows the synthesis of silylchalconium ions with control of the stereochemistry at the chalcogen atom (shown here for the sulfonium ion). The chalcogen neighboring group effect on the silyl cation is sufficiently strong to conserve the stereochemistry in a consecutive nucleophilic attack.

C−H Activation

Open Access

Insights into Ruthenium(II/IV)-Catalyzed Distal C−H Oxygenation by Weak Coordination

  • Pages: 16450-16454
  • First Published: 29 June 2020
Description unavailable

C−H hydroxylation of aryl acetamides and alkyl phenylacetyl esters is achieved via a challenging distal weak O-coordination by a ruthenium(II/IV) catalyst. The process includes C−H activation, ruthenium(II/IV) oxidation and reductive elimination which provides step-economical access to valuable phenols.

Nanocapsules

A Barrel-Shaped Metal–Organic Blue-Box Analogue with Photo-/Redox-Switchable Behavior

  • Pages: 16455-16462
  • First Published: 06 August 2020
Description unavailable

Lock, stock, and blue-box-like barrel: A unique self-assembled metal–organic nanobarrel is achieved by using electron-deficient viologen-based linkers and lanthanide ions. The resulting capsule encloses chloride anions and exhibits photo-/redox-responsive behavior, enabled by nearby electron donors.

Chemical Biology

Selective Hydrolysis of Terminal Glycosidic Bond in α-1-Acid Glycoprotein Promoted by Keggin and Wells–Dawson Type Heteropolyacids

  • Pages: 16463-16471
  • First Published: 16 July 2020
Description unavailable

A range of Keggin and Wells–Dawson type heteropolyacids have been shown to selectively hydrolyze terminal glycosidic bond in heavily glycosylated α-1-acid glycoprotein, resulting in the removal of sialic acids with no observed destruction of the protein core or the residual glycan chains.

Metallacycles | Very Important Paper

Cyclic Bis-alkylidene Complexes of Titanium and Zirconium: Synthesis, Characterization, and Reaction

  • Pages: 16472-16479
  • First Published: 01 September 2020
Description unavailable

In for a Schrock: The synthesis and characterization of five-membered cyclic Schrock-carbene-like bis-alkylidenes of titanium and zirconium are realized. These Schrock-carbene-like bis-alkylidenes show unique reactivity toward N,N′-diisopropylcarbodiimide, CO, cyclooctatetraene, and azobenzene.

Molecular Recognition

A Molecular Capsule with Revolving Doors Partitioning Its Inner Space

  • Pages: 16480-16485
  • First Published: 10 July 2020
Description unavailable

A newly designed covalent capsule incorporates three revolving pyridine “doors” splitting its inner space into two chambers that may coalesce into one. The chambers accommodate up to two haloalkanes in the allosteric fashion therefore opening a way for studying the effect of host internal dynamics on reactivity, noncovalent interaction or trafficking of guests residing in such unique environment.

Drug Design

Naphthoquinone–Dopamine Hybrids Inhibit α-Synuclein Aggregation, Disrupt Preformed Fibrils, and Attenuate Aggregate-Induced Toxicity

  • Pages: 16486-16496
  • First Published: 01 September 2020
Description unavailable

Break fibrils apart: Naphthoquinone–dopamine hybrid molecules (NQDA and Cl-NQDA) inhibit the aggregation of α-synuclein and disaggregate its preformed fibrils into non-toxic species. NQDA was found to cross a human blood–brain barrier model efficiently. These hybrid molecules can be an attractive scaffold for therapeutic design towards Parkinson's disease.

Photocatalysis

Bis-Anthracene Fused Porphyrin as an Efficient Photocatalyst: Facile Synthesis and Visible-Light-Driven Oxidative Coupling of Amines

  • Pages: 16497-16503
  • First Published: 27 July 2020
Description unavailable

Bis-anthracene fused porphyrin is synthesized in a high yield by a facile protocol. When serving as a photocatalyst, the new molecule exhibits excellent catalytic performance for visible-light-induced aerobic oxidation of amines to imines at ambient conditions.

Proton-Coupled Electron Transfer

Open Access

Evaluation of the Synthetic Scope and the Reaction Pathways of Proton-Coupled Electron Transfer with Redox-Active Guanidines in C−H Activation Processes

  • Pages: 16504-16513
  • First Published: 07 September 2020
Description unavailable

There's a good PECT! Redox-active guanidines are used in proton-coupled electron transfer (PCET) reactions that involve C−H bond cleavage. The study reveals the scope and the mechanism of PCET reactions with and without addition of a strong acid. Substrates with potentials of up to 1.2 V versus ferrocenium/ferrocene could be oxidized in stepwise PCET processes initiated by electron transfer. Experiments with guanidine derivatives show the possibility of tuning the PCET reactivity.

Carbon Materials | Hot Paper

Pitch-Based Laminated Carbon Formed by Pressure Driving at Low Temperature as High-Capacity Anodes for Lithium Energy Storage Systems

  • Pages: 16514-16520
  • First Published: 09 September 2020
Description unavailable

On the pitch: Pitch-based laminated carbon materials have been prepared at low temperature with the additional help of pressure. The prepared carbon materials can act as the anode in lithium-ion batteries and the lithium storage mechanism has been elaborated. A high stable capacity of approximately 550 mAh g−1 at 50 mA g−1 is obtained. Meanwhile, the lithium-ion capacitor based on the prepared carbon material has been assembled and it also exhibits a high performance.

C−H Activation | Hot Paper

Visible-Light-Enabled C−H Functionalization by a Direct Hydrogen Atom Transfer Uranyl Photocatalyst

  • Pages: 16521-16529
  • First Published: 09 September 2020
Description unavailable

Uranyl photocatalysis: An efficient and convenient C−H activation strategy by a direct hydrogen atom transfer process for the synthesis of high-value-added diarylmethane derivatives from p-quinone methides has been developed by combining a uranyl photocatalyst with visible-light irradiation (see scheme). EPR experiments and DFT calculations revealed that the formation of UV−O species by the reduction of UVI=O under visible light is responsible for the initial step of the photoinduced reaction.

Cluster Compounds

Tuning the Cell Uptake and Subcellular Distribution in BODIPY–Carboranyl Dyads: An Experimental and Theoretical Study

  • Pages: 16530-16540
  • First Published: 30 June 2020
Description unavailable

Round 1! Fluorophores bearing carborane clusters often display remarkably different cell incomes, with recurrent higher permeabilities for meta-carboranes compared to the ortho isomers. Here, we study a set of BODIPY-carborane dyads to provide an explanation for these differences, which originate from important variations in their partition coefficients and static dipole moments.

Medicinal Chemistry | Hot Paper

Molecular Recognition

Cationic FeII Triplex-Forming Metallohelices as DNA Bulge Binders

  • Pages: 16554-16562
  • First Published: 07 October 2020
Description unavailable

Preferred binding partners: Cationic FeII triplex-forming metallohelices prefer binding to bulged DNA, rather than double-stranded DNA. Their binding affinities towards bulges strongly depend on the bulge size and the base composition of the bulge loop.