This Minireview describes the resistance mechanism of bacteria producing β-lactamase and further summarize the fluorogenic probes/inhibitors of β-lactamase, and their applications in the treatment of infectious diseases. We provide guidelines for the design of fluorogenic probes with improved selectivity/sensitivity/effectiveness to identify further inhibitors for β-lactamases and eventually overcome bacterial resistance.

Nanoparticles with chaperone-like activity may be considered as potential therapeutic agents to treat conformational diseases. This Minireview aims at emphasising the essential features required by nanomaterials to deal with toxic protein misfolding and accumulation.

Single or Double? This Minireview highlights the recent new reactivities of frustrated Lewis pairs that disclose that certain combinations of Lewis acids and bases undergo single-electron transfer processes. In these studies, Electron Paramagnetic Resonance spectroscopy has been instrumental in the elucidation of reaction pathways.

Topochemische Reaktionen am reduzierenden Ende von Nanocellulose sind ein Trend in der Cellulosematerialforschung. Die Chemie ist Aldehyd-spezifisch und nutzt die inhärente Direktionalität der Ketten des Cellulose-I-Kristalles – mit allen Aldehydgruppen exklusiv an einem Ende. Ziel dieses Aufsatzes ist es, Herausforderungen der Endgruppen-selektiven Modifizierungen zu diskutieren und das Potential für neue Nanocellulosematerialien hervorzuheben.

Die Biokatalyse hat sich zu einer reifen Technologie für die Synthese von Chemikalien und Pharmazeutika entwickelt, wo sie durch hohe Selektivität und milde Reaktionsbedingungen Vorteile bringt. Dieser Aufsatz hebt aktuelle Erfolge hervor, mit besonderem Fokus auf industrielle Anwendungen und führt Leistungsindikatoren ein, um die Effizienz von Enzymverfahren zu beurteilen.

This Review discusses synthetic approaches to fullerene-based hybrids with low-dimensional (LD) materials and their properties. Recent advances in the design of fullerene-based LD nanomaterials for (photo)electrocatalytic applications are emphasized. The relationship between the electronic structures and the catalytic functions of the heterostructures is addressed to provide an understanding of these emerging materials at the molecular level.

The highest efficiency of photon upconversion from visible (vis) light to ultraviolet (UV) light is achieved based on the discovery of excellent UV emitter TIPS-naphthalene. By sensitizing the TIPS-naphthalene triplet with a superior donor Ir(C6)₂(acac) that does not quench UV emission, even weak visible light such as sunlight and room LEDs is efficiently upconverted to UV light.

Nanoparticle-assisted NMR spin relaxation applied to ubiquitin reveals a remarkable indifference of protein dynamics to nanoparticle charge and size. The data indicate the absence of significant amounts of slow timescale dynamics within the picosecond to low microsecond range.

The biosynthesis of the cinnamoyl lipid (CL) polyketide natural products youssoufenes involves an isomerase-dependent acyl carrier protein (ACP)-tethered polyunsaturated chain elongation process. The three ketosynthase/chain length factor (KS/CLF) complexes are revealed to act in harmony, assembling different parts of the carbon skeleton in a modular manner.

Addition of a carbene catalyst to vinyl carbonates initiates the aldol reaction. This aldol event is subsequently followed by an enantioselective acylation that is mediated by the same (chiral) NHC catalyst without introducing any additional substance. This post-aldol process takes care of the enantioselectivity issues and drives the otherwise reversible aldol reaction toward a complete conversion.

HIV-1 gp41 undergoes large structural rearrangements to mediate membrane fusion. Its membrane-proximal external region (MPER) segment, critical to soliciting neutralizing antibodies, is shown to spontaneously assemble into an α-helical trimer in aqueous solution.

Using the spiro-cyclization of amides as a benchmark reaction, the feasibility of photocatalytic aerobic iodoarene catalysis was demonstrated by relying on a pyrylium photocatalyst under blue light irradiation. This unprecedented dual organocatalytic system allows the use of low catalytic loading of both catalysts under very mild operating conditions.

A manganese-catalyzed kinetic resolution through asymmetric C(sp³)−H oxidation was applied to a wide range of five-membered 1,3-dihydroisobenzofurans and 2,3-dihydrobenzofurans as well as six-membered 6H-benzo[c]chromenes bearing diverse α-substituents with extremely efficient enantiodiscrimination (see scheme). Late-stage oxidative kinetic resolution of bioactive molecules that are otherwise difficult to access was further demonstrated.

A B,N co-coordinated catalyst (denoted Zn-B/N-C) has been fabricated wherein the s-band of Zn⁺ has been manipulated. The ORR efficiency is maximized by the B₂-Zn-N₂ configuration, which holds enough Zn 4s electrons to guarantee favorable adsorption of O₂ as well as visible charge transfer. The catalyst shows excellent long-term stability in both acid and alkaline environment.

A photocatalytic system was developed for perfluoroalkylation of vinyl-substituted all-carbon quaternary centers by using perfluoroalkyl halides with concomitant 1,2-aryl migration. This strategy possesses good functional-group compatibility and can serve as a powerful synthetic tool for the construction of valuable perfluoroalkylated compounds that would be difficult to prepare by other methods.

An unprecedented methylation of various iminoamido heterocycles by using Corey–Chaykovsky reagents is described. The use of aqueous solvent in the coupling reaction and the selective methylation and alkylation of azauracil nucleosides are highlighted.

Coreactant-Embedded ECL Microimaging: A dual intramolecular electron transfer strategy is designed for construction of a coreactant-embedded ECL microimaging system. The proposed tertiary amine conjugated Pdots and imaging system realize the visual analysis of membrane protein on single living cells and in situ evaluation of its expression change upon drug treatment.

Amyloid-based minimalistic systems are shown to demonstrate diverse cascade reaction networks, from simple two-step, to multistep, to complex convergent cascades. Further, complex chemoelectronic computations were performed with the help of multi input, concatenated AND gates.

The yet underdeveloped coordination chemistry of Ga^I species won a new addition to their family. With an unprecedented bonding situation in main-group chemistry, the complex salt Ga(COD)₂⁺[Al(OR^F)₄]⁻ (COD=1,5-cyclooctadiene; R^F=C(CF₃)₃) offers novel options. Its properties are compared with respect to those of related transition-metal species.

Bicyclo[1.1.0]butyl boronic ester (BCB-Bpin) reacts with a diverse range of heteroatom (O, S, N)-centred nucleophiles, with exclusive α-selectivity. In contrast, sterically hindered bis-sulfonamides react at the β′-position leading to cyclopropanes with high trans-selectivity.

Regio-controlled hydromagnesiation of 1,3-enynes was enabled by magnesium hydride. Subsequent downstream alkylation and silylation allowed for construction of tri- and tetra-substituted allenes.

The amplification of circularly polarised (CP) luminescence of a small chiral molecule embedded within an achiral polymer matrix is demonstrated. This amplification (from |g_PL|=0.0003 to 0.15) is observed in several achiral polymer hosts, due to electrodynamic coupling between the electric and magnetic transition dipoles of the donor (polymer) and acceptor (small molecule), which results in efficient CP Förster resonance energy transfer.

We use a phosphinoborane frustrated Lewis pair (FLP) ligand to stabilize ER₂ species (E=Si, Ge; R=H or Me) for the subsequent deposition of semiconductor elements and polymers from solution. The ability to recycle the FLP phosphine-borane ligand after element deposition is also demonstrated.

Bitte klammern! Terminale Helixwindungen eines heterodimeren Coiled Coils wurden mittels einer kovalenten Lactambrücke oder einer reversiblen Metallkoordinationsbindung geklammert. Die Klammern erhöhen den Widerstand gegen die Entfaltung der Helices und erhöhen die Stabilität des Coiled Coils gegenüber thermischer Denaturierung und extern wirkenden Kräften.

Ein rein organischer kolloidaler Kern-Schale-Katalysator wurde durch eine zweistufige tensidfreie Emulsionspolymerisation hergestellt. Der kolloidale Säure/Basenkatalysator eignet sich für praktische Anwendungen aufgrund seiner hohen katalytischen Aktivität in Wasser, Aufskalierungs-Möglichkeiten und einfachen Rückgewinnung.

Das erste heteronukleare Vinylanion aus zwei schwereren Elementen der Gruppe 14, das Silagermenid 3⋅K(18-c-6), ist durch KC₈ Reduktion eines NHC-stabilisierten Germylens oder des entsprechenden NHC-freien Digermens zugänglich. Die Anwendbarkeit als Synthon in der Synthese von präzedenzlosen funktionalisierten Silagermenen 4 a,b und eine erhebliche π-Konjugation zwischen den N=C und Si=Ge Doppelbindungen werden beschrieben.

Die Kombination eines chiralen Kupferkatalysators und eines bifunktionalen Rutheniumpincerkomplexes ermöglicht die nichtenzymatische dynamische kinetische Racematspaltung von acyclischen und cyclischen Benzylalkoholen. Die enantioselektive Cu-H-katalysierte dehydrierende Si-O-Kupplung und die übergangsmetallkatalysierte Racemisierung des Alkohols sind vollkommen orthogonal, wodurch hohe Ausbeuten und gute Enantioselektivitäten erreicht werden.

Benzoesäure und Benzamidin sind, mit korrekten pK_a-Werten versehen und mit geeigneten elektronenziehenden und -schiebenden Gruppen entworfen, bioisoster hinsichtlich ihrer Bindung an die Scharnierregion einer Kinase.

Constructing phase-junction electrocatalysts could effectively accelerate the Volmer step and modulate the electronic structure at the interface. NiP₂-650(c/m) shows an overpotential η₁₀ of 134 mV vs. RHE at 10 mA cm⁻² and a Tafel slope of 67 mV dec⁻¹, which is significantly reduced by 26 % and 96 % compared with c-NiP₂ and m-NiP₂, respectively.

We find a new mechanism of strong band convergence with low onset temperature for p-type PbSe. The discordant Ag doping raises the heavy hole band and Sr/BaSe alloying lowers the light hole band, leading to the fast and strong band convergence and significantly enhanced Seebeck coefficient.

The Mn−O covalency was enlarged by the Co sites mainly in the octahedral configuration, which results in a decreased charge transfer energy to favor Mn–PMS interaction and enhance Mn^IV reduction to boost PMS activation activity of Co-Mn spinel oxides.

A cocrystal packing arrangement has been tuned from mixed to segregated stack by subtle modulation of halogen bonds from C−Br⋅⋅⋅N to C−I⋅⋅⋅N, giving rise to significantly enhanced radiative decay rate and selectivity. Amplified spontaneous emission characteristics were improved remarkably by cocrystallization, opening up possibilities to the development of organic lasing materials by tailoring multiple radiative decay pathways.

Electrocatalytic hydrogenation of benzaldehyde to benzyl alcohol on carbon-supported metals proceeds through proton-coupled electron transfer. The presence of polar co-adsorbates such as phenols enhances the hydrogenation rate of the aldehyde by the polarization of the carbonyl group because of the formation of a hydrogen bond. Increasing either the concentration or acidity of the co-adsorbate increases the rates of selective carbonyl reduction.

1,2-Alkynylallylation of a specific C−C σ bond in cyclopropenes was realized by a simple, neutral, low-cost palladium catalytic system with high TONs. This decarboxylative reorganization reaction is an efficient way to construct highly functionalized dienynes in excellent regio- and stereoselectivity. A nonclassical β-C elimination promoted by 1,4-palladium migration was described herein for the first time.

A Mn-porphyrin-based catalytic method that enables access to two different classes of nitrogen heterocycles is reported. Mechanistic investigations found that a 1,3-cycloaddition click reaction occurs directly via the Mn-bound complex, whereas denitrogenative annulation proceeds through an Mn-N complex. The reported method is compatible with a wide range of substrates for both reactions.

By incorporating azobenzene photochromic units in the double functionalization of [60]fullerene, the regiochemistry of the double cyclopropanation reaction could be controlled by using either the E or the Z isomeric forms of the photoswitch. Once covalently linked to the C₆₀ sphere, the azobenzene unit changes its light- and thermally-induced isomerization properties.

Nanoassembly can play a key role in generating effective vaccines for emerging (SARS-CoV-2) and established (influenza) pandemic threats. SpyTag-mediated display was used to adapt the nanocage to the challenge of bacterial or viral antigens with diverse cyclic and dihedral symmetries. Establishing display of both trimeric and tetrameric antigens may lead to an influenza vaccine with broader protection.

Novel Diels–Alder polymer networks with tunable aggregation-induced emission (AIE) behavior, constructed from non-emission dimaleimide-substituted tetraphenylethene and linear furan-based copolymers, have a tunable fluorescent „turn on/off“ property, which shows an accurate response to temperature.

Programmable DNA-based reaction–diffusion processes form self-stabilizing spatial patterns at a length scale of tens to hundreds of microns. Such patterns can recapitulate the function of feedback control algorithms to repair damage, which is demonstrated using UV light-triggered competition reactions that consume the patterned species.

We have designed an efficient N₂ reduction reaction (NRR) catalyst with diatomic Pd-Cu sites on N-doped porous carbon by modifying single-atom Pd sites with Cu. The catalyst achieves high Faradaic efficiency and a desirable yield rate for NH₃ electrosynthesis under ambient conditions, outperforming the individual single-atom counterparts.

By switching the clearance route of indocyanine green (ICG) from liver uptake to renal tubular secretion with low molecular weight PEGylation, we were able to hyperfluorescently image kidney cancers and their metastases with no need for ligand-receptor-mediated active targeting.

Germanane was synthesized by topotatic deintercalation of β-CaGe2 in aqueous HF solution at room temperature under stirring for 2-3 minutes. In order to remove the residual CaF₂ the material was treated with a saturated aqueous solution of EDTA.

Substituted carboranes with -SeMe, -TeMe, and -I groups on the skeletal carbon vertices are shown to be outstanding chalcogen bond (ChB) and halogen bond (XB) donors to recognize halide anions. Moreover, the interactions are found to be remarkably efficient with short distances and high directionality. Theoretical calculations further validate the presence of a deep σ-hole on Se, Te, and I.

The advanced Pd catalyst system with Neolephos as a ligand enables highly selective hydroamidation of unbiased (un)symmetrical 1,3-diynes. In this way, a wide range of synthetically useful α-alkynyl-α,β-unsaturated amides are afforded in good to high yields with excellent chemo-, regio-, and stereoselectivities.

The use of a cinchona-alkaloid-derived N,N,P-ligand leads to the direct enantioconvergent coupling of racemic alkyl bromides with azole C(sp²)−H bonds by copper catalysis. The key to success is the ligand-enabled facile oxidative addition at approximately room temperature that suppresses product racemization at elevated temperature. This method provides a range of enantioenriched α-chiral alkylated azoles.

Glycosyl sulfoxides appended with an aryl iodide moiety were shown to be readily available, air and moisture stable precursors to glycosyl radicals. The use of these radical precursors enabled the synthesis of various complex C-linked glycoconjugates under mild conditions.

Single rhodium ions on ceria are the active species for nitric oxide (NO) reduction by carbon monoxide (CO) in the low-temperature regime in dry and wet gas streams: only a small amount of expensive rhodium around 0.1 wt % is needed to produce active catalysts with very high turn-over frequencies >300 h⁻¹, full NO conversion below 150 °C and stable time-on-stream performance.

A practical coupling of (hetero)aryl halides with hydrazine to form (hetero)aryl hydrazines, with loadings down to 100 ppm of a Pd catalyst and KOH as base is reported, along with detailed mechanistic data revealing the factors that control the rate and selectivity. Two catalyst resting states are observed, but one major pathway involving rate-limiting deprotonation of hydrazine bound to an arylpalladium(II) chloride complex occurs.

Crystal-facet-dependent catalytic performance for CO₂ reduction has been observed in Ni-based 2D MOLs. Ni-MOL-100 displays much higher catalytic activity than Ni-MOL-010, benefiting from the synergistic catalysis between two adjacent Ni sites in Ni-MOL-100.

Unconventional synthesis guided by machine-learning and in situ X-ray diffraction allowed the new type of inorganic clathrate K₅₈Zn₁₂₂Sb₂₀₇ to be synthesized. This compound is a rare case of an inorganic clathrate which does not contain Group 14 elements, as well as being a structure not seen previously among clathrates. X-ray diffraction and STEM reveal a complex structure with promising thermoelectric properties.

[4Fe-5S] clusters are emerging as possible key catalytic intermediates in various sulfuration and desulfuration reactions. A structurally characterized [4Fe-5S] intermediate, resulting from the transfer of a sulfur atom from thiouracil to the [4Fe-4S] cluster of an enzyme, suggests that [4Fe-4S] clusters can function as sulfur transfer agents.

Putative G4-forming sequences (PQSs) in SARS-CoV-2 have been verified to form stable RNA G-quadruplex structures in live cells. G4-specific targeting compounds, such as PDP (pyridostatin derivative), can stabilize this structure and decrease the protein levels of SARS-CoV-2 N by inhibition of its translation both in vitro and in vivo.

The on-surface synthesis approach under UHV conditions has led us to the formation of 1D coordination π–d conjugated polymers on metal surfaces. The reaction of quinoidal ligand with different transition metals results in two distinct coordination motifs: four-fold (Cr, Fe, Co, Ni) and two-fold (Cu). The backbone of the Cu-coordinated 1D chain is formed by antiaromatic 12-membered macrocycles.

Total synthesis allowed the identification of the most likely stereostructure of the cytotoxic marine macrolides of the formosalide family (see structure) from eight possibilities. The successful route was based upon an inherently flexible blueprint that builds all stereogenic centers by strictly catalyst controlled transformations prior to formation of the polycyclic framework by late-stage alkyne metathesis followed by a π-acid-catalyzed transannular cyclization.

Thermochromic metal complexes of bipyridyl ligands and their gels were shown to have broad application in controlled light transmission windows and logic operations. Herein, temperature is used as a precision input for effecting reversible multi-step changes in the optical properties of metal–organic complexes. Such systems form archetypical prototypes for sequential logic enabled volatile multi-state memory and arithmetic operators.

The size-controlled Cu catalysts from single atoms to subnanometric clusters (0.5–1 nm) to nanoclusters (1–1.5 nm) on a graphdiyne matrix are prepared by an acetylenic-bond-directed site-trapping approach. Size dependence of activity and selectivity in the CO/CO₂ reduction reaction (CO/CO₂RR) over these catalysts is shown for the first time.

N₂ and O₂ cleavage was achieved under ambient conditions via a cooperativity between U^III and P^III centers. The N₂ triple bond breaking implies a U^III–P^III six-electron reduction. The interaction between U^III and P^III in this molecule allows an eight-electron reduction of two O₂ molecules. This study shows that metal–ligand cooperation is a promising strategy for the activation of small molecules.

S-Adenosyl-L-methionin-Analoga bieten die Möglichkeit, die Zielstellen von Methyltransferasen zu studieren. Ihre enzymatische Herstellung war bisher auf aliphatische Gruppen am Schwefel-Atom beschränkt. Wir konnten nun SAM-Synthetasen entwickeln, die AdoMet-Analoga mit Photoschutzgruppen herstellen. Durch Kombination mit DNA-MTasen gelingt das sequenz-spezifische Anbringen und das lichtabhängige Entfernen von Modifikationen an Plasmid-DNA.

Voraussetzungsfreie Struktursuchansätze haben zur Vorhersage von kristallinen Carbodiimiden, Guanidinaten und Orthonitridocarbonaten geführt, wobei letztere erstmals das Strukturmotiv des Diamants in die Hochdruckstickstoffchemie fester Materie einbringen. Mehrere dieser neu erkannten Phasen dürften vielversprechend für die Anwendungsgebiete der photoelektrochemischen Wasserspaltung und der nichtlinearen Optik sein.

Während in der Chemie gewöhnlicher Organolithiumverbindungen Dimere generell als stabiler als solvatisierte Monomere und Natrium- und Kaliumorganyle als noch reaktiver gelten, scheint sich dieser Trend für Carbenoide umzukehren. DOSY-NMR, SC-XRD-Analysen sowie quantenchemische Studien anhand eines chiralen Modellsystems zeigen bemerkenswerte Unterschiede in den Stabilitäten und Strukturen in Abhängigkeit vom Lösungsmittel.

C-N-Isomerisierungsreaktionen an anionischen bi-mesoionischen Carbenliganden auf Boratbasis werden beschrieben. Die Co^II-Komplexe mit diesen Liganden zeigen Geometrien, Spinzustände und Reaktivitäten, die durch agostische Wechselwirkungen in der sekundären Koordinationssphäre gesteuert werden.