Finally stereoselective: Enantioselective variations have been developed for many multicomponent reactions; however, it has been missing for the Ugi four-component reaction. This has now changed with the discovery of an efficient catalytic enantioselective variant for the four-component reaction of isocyanides, primary amines, aldehydes or ketones, and carboxylic acids.

The soft touch: Polyatomic ions with well-defined composition, charge state, and kinetic energy can be deposited onto surfaces by ion soft landing. This preparative mass-spectrometric approach affords not only uniform molecular and ionic layers, but also three-dimensional architectures.

Active vesicles: Min proteins were encapsulated in giant liposomes. This not only caused the proteins to self-organize and form oscillatory, spatiotemporal reaction–diffusion patterns on the vesicle membranes, but also had an unexpected effect on lipid bilayer dynamics: The periodic binding and disassociation of the proteins to and from the membrane induced changes in membrane curvature, leading to oscillations in the overall shape of the vesicles.

FRETter by design: Three subphthalocyanine (SubPc)/pentacene dimer (Pnc₂) conjugates were prepared for the synergy of panchromatic light absorption, energy transfer, and intramolecular singlet fission (SF). Transient absorption measurements confirmed the reaction sequence of light harvesting by the SubPcs, unidirectional Förster resonance energy transfer (FRET) from the SubPcs to the Pnc₂, and almost quantitative intramolecular SF.

Enantiopure alleno-acetylenic cage receptors display a fourfold circular hydrogen-bonding network of one handedness. Alcohol guests expand the hydrogen-bonding network of the receptor, forming hydrogen-bonding topologies reminiscent of those found in isolated water clusters: circular fourfold & docking, pentagonal, linear fivefold, and boat-shaped hexagonal. The expansion is accompanied by a gain in Gibbs binding energy.

Molecular poetry: YEATS domain (YD) containing proteins are an emerging class of epigenetic protein targets in drug discovery. A screening hit has been developed into the first potent, selective, and cell-active chemical probe for the YD-containing proteins MLLT1 and MLLT3. The probe represents the first inhibitor of its class to explore YD-associated biology and disease links.

Nickel for cobalt: F430 is a unique enzymatic cofactor in the production and oxidation of methane by strictly anaerobic bacteria. The key enzyme methyl coenzyme M reductase contains a hydroporphinoid nickel complex. A hybrid nickel(II)-containing corrinoid that partly resembles F430 in its structural and spectroscopic features was obtained in a three-step semisynthesis from vitamin B₁₂.

Electrons instead of X-rays: An electron diffractometer was tailored and employed for de novo structure determination from submicrometer-sized crystals. A new methylene blue derivative was analysed together with a microcrystalline extract of an active pharmaceutical ingredient from a pill. The results obtained on submicrometer-sized samples complement X-ray crystallography.

An exceptional radical: Tetracyano-naphthalenediimide and its radical anion have been isolated and subjected to structural elucidation through spectroscopic and X-ray diffraction studies. The planar radical anion is supramolecularly stabilized and electrochemical studies confirm its extraordinarily low-lying LUMO (−5.0 eV), rendering it one of the strongest electron-deficient planar π systems to be isolated.

By a whisker: Helical fibers with the lengths of micrometers are prepared on silicon wafers by evaporation-driven self-assembly of functionalized cellulose nanowhiskers (CNWs) with surface-attached acyl chains.

Molecularly precise: A series of reduced dinuclear μ-phosphido complexes have been prepared as models for heterogeneous proton reduction catalysts. These molecular complexes provide insight into elementary reaction steps and thermochemical parameters relevant to their solid-state counterparts. μ-P protonation, Mo-to-P H-migration, and H-atom transfer have all been demonstrated, en route to H₂ formation.

The formation of a one-dimensional solid, its hydration, and its dissolution on a Ag(111) surface were followed by low-temperature scanning tunneling microscopy. The annealing of dry chains results in a simple increase in chain length and number whereas the annealing of water-decorated chains results in a complete loss of order and produces water clusters decorated with the organic molecule.

To the “CO₂RR”: Metal phthalocyanines (MePcs) with well-defined metal–N₄ structures were used as model catalysts to study the active centers and reaction mechanisms for the electrocatalytic CO₂ reduction reaction (CO₂RR). Theoretical and experimental studies identify CoPc as the optimum catalyst for the selective electrocatalytic CO₂RR to deliver CO. The Co site serves as the active center for achieving a Faradaic efficiency (FE) of up to 99 % with long-term stability.

A thermally responsive and microstructured graphene/poly(N-isopropylacrylamide) (mG/PNIPAm) membrane was used for intelligent solar water evaporation. In response to varying sunlight intensities, the water evaporation rate of this leaf-like mG/PNIPAm membrane is tuned through opening and closing the water transport channels in a process similar to the stomatal opening/closing of leaves.

Poised to react: Macrocyclic cycloparaphenylenes with built-in alkynes are presented and the impact of strain on the structural/electronic properties of the alkyne investigated. The angle-strained alkynes demonstrate a size-dependent reactivity profile that permits [2+2]cycloaddition-retrocyclization and copper-free azide–alkyne coupling reactions under mild conditions.

Nanoparticles formed by self-assembly of amphiphilic block copolymers were investigated for their potential application in photodynamic therapy. The porphyrin-containing polymeric nanoparticles display high photochemical yield and phototoxicity in vitro and in vivo, thus providing a novel strategy to enhance the PDT efficacy.

Staying active: A sulfo self-dopant of polyaniline (PANI) functioned as an internal proton reservoir, so that the electrochemical activity of the polymer was preserved in weakly acidic ZnSO₄ aqueous electrolyte (see picture). In a full zinc cell, the self-doped polyaniline cathode showed a high capacity of 180 mAh g⁻¹, excellent rate capability, and a long cycle life of over 2000 cycles with almost 100 % coulombic efficiency.

The extracellular part of the NR1 domain of the NMDA receptor was labelled by genetic code expansion in combination with bioorthogonal click chemistry. Receptor labeling with small organic dyes has advantages over immunocytochemistry protocols in live-cell and super-resolution imaging.

Two ions in the fire: A multi-ion strategy to improve the electrochemical performance of sodium-ion full batteries is presented. The optimized sodium-ion-based multi-ion battery achieves a high working voltage of about 4.0 V, superior rate capability (up to 30 C; capacity retention: 87 %), and long cycling stability over 500 cycles at 5 C (capacity retention: 95 %).

Think big: The structural characterization of large biological systems is a challenge by conventional techniques. Fast MAS ¹⁹F NMR spectroscopy was found to be an attractive means for investigating protein assemblies (see picture). In the investigation of HIV-1 capsid protein assemblies, high spectral resolution was attained in ¹⁹F–¹⁹F correlation spectra, permitting the detection of nanometer distances of the order of 20 Å.

(B)rush order: “On water” surface-initiated Cu-mediated controlled radical polymerization (“on water” SI-CuCRP) is presented. By using this approach hydrophobic monomers in aqueous reaction medium and in the presence of oxygen are converted to polymer brushes at unparalleled speed and efficiency.

One probe to see them all: complex behavior of discrete phases of a heterogeneous polymer can be directly imaged by robust phosphorescent mechanophores. Hard phase rearrangement, breakdown, and crystallization were shown to have distinct optical response patterns that makes it possible to track and identify these diverse deformation mechanisms.

Plasma membrane permeabilization by antifungal cationic amphiphiles is the first of a series of events that occur inside fungal cells. Inside the cells these antifungal agents rapidly induce structural changes in macromolecules and organelle disassembly.

Teamwork: An aggregation-induced emission fluorogen was combined with a liposome to yield an AIEgen–lipid conjugate (“AIEsome”). The AIEsome exhibits bright red fluorescence and strong photosensitization along with great photostability and biocompatibility, and can be used for image-guided photodynamic therapy for in vitro cancer cell ablation and in vivo antitumor therapy. PDT=photodynamic therapy, ROS=reactive oxygen species.

Alarming trend: High resolution mass spectrometry revealed hundreds of previously unknown halogenated contaminants in polar bear serum. A mouse study confirmed the 5 new PCB metabolite classes. Stable time-trends of PCB metabolites and increasing fluoroalkyl contaminants in polar bear serum between the mid-1980s and 2016 make toxicological studies on these new contaminants warranted.

Rapid and efficient utilization of triplet states to generate room temperature phosphorescence (RTP) or highly efficient thermally activated delayed fluorescence (TADF) is achieved by structural modification to give a planar or twisted intramolecular charge transfer (PICT or TICT) geometry, respectively.

Keeping it local: Incorporation of flavin cofactors (FMN) within the local hydrophobic microenvironment of a modified polyethyleneimine allows activation of dioxygen in the presence of NADH. This activation results in a successful Baeyer–Villiger reaction at room temperature in water.

Ozone overthrown: The iron containing metal–organic framework MIL-100(Fe) exhibits a long-lasting ozone conversion efficiency of 100 % for over 100 h under 45 % relative humidity, which is well beyond the performance of most porous or metal catalysts such as activated carbon and α-MnO₂. MIL-100(Fe) has also been incorporated into air filters for efficient protection against ozone under humid conditions.

The use of Ar/O₂ plasma facilitates exfoliation, cubic-to-orthorhombic phase transformation, and surface oxidative reorganization in cobalt diselenide (CoSe₂). This leads to the optimal chemical and electronic structure for OER electrocatalysis.

Controlled metathesis: Metathesis between disulfide and diselenide bonds was realized under irradiation, and the conversion of the exchange reaction could be controlled by modulating the wavelength of the light. This chemistry was applied to polymer materials to control the cleavage of polymers from a distance.

A C₂-symmetric resorcinol derivative was used in the enantioselective, catalytic vicinal difluorination of alkenes by I^I/I^III catalysis. The HF:amine ratio employed in this process provides a handle for regioselective orthogonality as a function of Brønsted acidity. Selectivity reversal from the 1,1-difluorination pathway (geminal) to the desired 1,2-difluorination (vicinal) is disclosed.

Superdrying: Microwave-enabled fast evaporation of water and decomposition of nitrate converted a metal–agarose framework into a 2D nanosheet structure. Using this approach, hybrids such as hollow Fe₃C nanoparticles, Ni/Co nanoparticles, and hollow FeO_x nanoparticles uniformly embedded in 2D graphitic carbon nanosheets could be obtained after annealing.

Three's a crowd: A polyfluorinated, trinuclear copper complex absorbs ethylene and undergoes a major structural rearrangement leading to a dinuclear copper–ethylene complex. Upon removal of ethylene it reverts back to the trinuclear species. This process occurs both in solution and in the solid state.

Quantum dots (QDs), a class of promising nanoparticles for visible-light harvesting, commonly possess low activity and selectivity towards photocatalytic CO₂ reduction. Doping CdS QDs with transition-metal cations, which can trap photoexcited electrons and suppress H₂ evolution, provides an approach to visible-light-driven highly selective CO₂ reduction with excellent durability.

Discrete gold nanorods (Au NRs) with strong chiroptical responses in the visible and near infrared region were synthesized by a seed-mediated approach in the presence of l- or d-cysteine. The chiral Au NRs can be further stabilized by a silica coating (lower pictures). Assembly of the chiral Au NRs (right pictures) with glutathione further improved the g factor.

Nanoparticles in nanoreactors: Hollow mesoporous silica nanoreactors with small metal oxide nanoparticles inside their cavities were obtained by deposition of silica onto metal-containing polymer micelles and subsequent calcination. The Co_xO_y-containing mesoporous silica nanoreactors were used as catalysts for the degradation of methylene blue and new coccine with hydrogen peroxide.

Balancing act: A novel strategy to manipulate the intracellular cofactor balance for whole-cell biotransformations based on a synthetic flavin analogue is reported. The synthetic flavin analogue can directly permeate into E. coli cells and accelerate cellular NAD⁺ regeneration without requiring cell-membrane modification.

Self-destruction for good: A substrate is shown to induce the self-assembly of a cooperative catalyst, leading to its own destruction. Nature exploits the same strategy to obtain high-energy structures such as microtubules and to drive non-equilibrium phenomena.

With ease! Already at −70 °C in liquid ammonia elemental selenium is inserted into the ionic A^I⋅⋅⋅C bond of A^IC₂H (A^I=K, Rb, Cs) to form the ⁻Se-C≡C-H anion previously unknown in crystalline compounds.

In sync with zinc: A dinuclear heterometallic CoZn catalyst shows much higher photocatalytic activity than the corresponding dinuclear homometallic CoCo and ZnZn catalysts, or the mononuclear Co and Zn catalysts for CO₂ reduction under the same conditions. The high performance of the CoZn catalyst is due to the enhanced dinuclear metal synergistic catalysis (DMSC) effect between Zn^II and Co^II.

An off and on relationship: In strongly acidic aqueous solutions, the oxime bond is dynamic and allows both a catenane and a macrocycle to self-assemble in relatively high yields. The dynamic nature of oxime linkage could be turned OFF almost fully in neutral conditions, making the self-assembled catenane kinetically inert in both solid state and solution at elevated temperatures or during chromatography and counteranion exchange.

Two in one sweep: A doubly reduced 9,10-diboraanthracene splits CO₂ quantitatively and under ambient conditions to give CO and carbonate ions. If lithium metal is used as the reducing agent, Li₂CO₃ precipitates from the reaction mixture and the CO₂ reduction process becomes catalytic.

Present and correct: A detailed protein data bank analysis in combination with quantum calculations showed that a significant number of carbon bonds (C-bonds) are present in proteins. These C-bonds contribute enthalpically to the overall hydrophobic interaction and play a significant role in the photodissociation mechanism of myoglobin and the binding of nucleobases to proteins.

Constant improvement: Covalent organic framework films with ultralow dielectric constants have been prepared by interfacial polymerization. These films feature thermal robustness, good flexibility, tunable dielectric constant, and high resistance to moisture and bending, providing great potential in portable electronic devices.

Visualizing cell viability: A fluorescent probe capable of reversible migration between mitochondria and nucleus dependent on cell viability and labelling the two organelles in dual colors has been developed. With the probe, mitochondria and nucleus can be visualized in dual emission channels, and cell viability could be evaluated by intracellular emission color and probe localization.

Holey suitable: Ultrathin N-doped holey carbon@graphene was synthesized and used as high-performance oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalyst in both alkaline and acidic media.

A highly congested tri(9-anthryl)methyl radical was successfully synthesized by circumventing the steric hindrance imposed by the bulky groups surrounding the central methyl carbon atom. Owing to its congested structure, the mesityl-substituted tri(9-anthryl)methyl radical is remarkably stable, which facilitates its handling under ambient conditions.

Surrogates: A highly chemo- and regioselective direct palladium-catalyzed C-allylation of hydrazones was developed using umpolung carbonyls as a source of unstabilized alkyl carbanions and surrogates of highly reactive alkyl organometallic reagents. The method requires only a catalytic amount of both metal and ligand, delivers products in high yields, is easily scaled-up, and demonstrates wide substrate scope and good functional-group compatibility.

The nature of H-atoms adsorbed on metal nanoparticles (NPs) is of major importance in many catalyzed reduction processes. The H-atoms of the transient {(M⁰-NP)-H_n}ⁿ⁻ behave mainly as hydrides when n is large (the Heyrovsky mechanism), and as atoms when n is small (the Tafel mechanism). The relative contributions of the two mechanisms differ considerably for Au and Ag-NPs.

Sustainable growth: A strategy for controlling the crystallization kinetics and improving the quality of engineered self-assembled 3D DNA crystals is reported. By using a rationally designed agent to modulate the crystallization process, fewer, but larger, crystals that yield diffraction patterns with modestly higher resolution are produced.

Three in one: Efficient one-pot multiple peptide ligation through repetitive native chemical ligation (NCL) and the removal of allyloxycarbonyl (Alloc) groups with a palladium complex was facilitated by 4-mercaptophenylacetic acid (MPAA; see scheme). This thiol additive for NCL also functioned as a scavenger for π-allyl palladium complexes and quencher of the resulting palladium(0) complexes.

Locked in: An intriguing advance in living anionic polymerization (LAP) by a “locked-unlocked” mechanism was investigated. The living anionic species can be quantitatively locked by end-capping with 1-(tri-isopropoxymethylsilylphenyl)-1-phenylethylene (DPE-Si(O-iPr)₃) and can be unlocked by adding the key, sodium 2,3-dimethylpentan-3-olate (NaODP).

On the move: A migratory geminal difluorination of aryl-substituted alkenyl N-methyliminodiacetyl (MIDA) boronates using commercially available Py⋅HF as the fluorine source is reported. The protocol offers an unprecedented opportunity for the synthesis of α- and β-difluorinated alkylboron compounds. Mild reaction conditions, broad substrate scope, good functional-group tolerance, and moderate to good yields were observed.

One-pot strategy: A simple gold(III) catalyst enables the construction of 2-aminopyrroles and quinoline-fused polyazaheterocycles from ynamides and anthranils under mild reaction conditions. This strategy uses readily available starting materials, proceeds in a highly step- and atom-economical manner, with broad substrate scope and scale-up potential.

A highly efficient asymmetric tandem reaction of N-sulfonyl-1,2,3-triazoles with two types of allyl alcohol esters was achieved by using a bimetallic rhodium(II)/chiral N,N′-dioxide–indium(III) complex catalyst. A series of β/γ-amino acid derivatives bearing different substituents were obtained in a good to excellent diastereo- and enantioselective manner.

Superelectrophilic dications formed by the double protonation of heteroatom functionalized carbonyl compounds were introduced conceptually and studied in situ in the seminal work of Olah. By employing sterically demanding and strongly electron-releasing N-heterocyclic iminato substituents, the first such example, [(IDippNH)₂CO]²⁺, has been structurally characterized.

Two mechanistically distinct modes of reaction—Cu-catalyzed bromo- and hydroalkynylations—are described for unsymmetrical arynes. These reactions are efficient, broad in scope, and give complementary alkynylation products. Mechanisms are proposed and potential for synthetic elaboration is demonstrated.