Self-navigation: The chemotactic micro- and nanodevices are a specific group of machines capable of autonomous navigation in their environment. The capability of sensing a concentration gradient of a chemical compound differentiates them from other microdevices and allows possible applications in areas unavailable to externally driven systems. The current developments in the area is summarized and discussed.

A pillar of the community: In 2008, a new class of macrocycles, “pillar[n]arenes” was discovered. This Minireview describes application of pillar[n]arene-based supramolecular assemblies for supramolecular gel formation, reactions, light-harvesting systems, drug-delivery system, biochemical applications, separation and storage materials, and surface chemistry.

Self-propelled active swimmers, while transducing chemical energy into mechanical motion, considerably influence the dynamics of their surroundings. The controlled propulsion of motors offers the ability to impart and manipulate the motion of dispersed objects in liquids, which enables interaction principles of non-equilibrium systems to be identified and the behavior of dynamically coupled particle assemblies to be harnessed for useful applications.

Copper helps out: The weakening of the CO adsorption energy on Ru atoms by alloying with Cu atoms plays an important role in the enhancement of the CO oxidation activity of Cu_xRu_1−x nanoparticles. The weakening of the CO adsorption energy on Ru atoms originating from the CO adsorption site change was confirmed by experimental and theoretical investigations.

Octopus chip cell capture: Inspired by the high efficiency of the prey mechanism of the octopus, an aptamer-tailed octopus chip (AP-Octopus-Chip) for CTC enrichment was developed. The design of the chip and the high binding affinity of the multivalent structures against the target cells significantly improved the CTC capture efficiency and enrichment. The enriched cancer cells can be released through a thiol exchange reaction, which is fully compatible with downstream mutation detection and CTC culture.

The high-oxidation-state complex Sb^V(TFA)₅ is capable of selective C−H functionalization of methane and ethane to their corresponding mono and/or diol trifluoroacetate esters. Experimental and computational studies support a unique C−H activation mechanism mediated by Sb^V, which is then followed by functionalization of an organoantimony intermediate.

Leader-free to d: Post-translational modifying enzymes from ribosomally synthesized peptide natural products offer new opportunities for small-molecule bioengineering. The in vitro analysis of an S-adenosyl-l-methionine radical enzyme is reported that generates d-amino acids in the core region of its native precursor protein substrate, as well as in leaderless linear and cyclic cores.

Helical polymerization: The porous metal-helix frameworks from the short α,γ-hybrid peptide foldamers terminated by the metal coordinating bis(pyridyl) ligands and silver ions are reported. These results suggest that helical foldamers can be used as templates to design new metal-helix frameworks.

Full Metal Jacket: Zinc dendrites pulse-deposited on silver foam convert CO₂ to CH₃OH with a Faradaic efficiency (FE)_CH₃OH of 10.5 % and a j_CH₃OH of −2.7 mA cm⁻² in aqueous solution. Strained, undercoordinated zinc atoms were identified as the active sites in a reaction pathway mediated by adsorbed CO and formaldehyde. Surprisingly, the stability of the *CHO intermediate does not influence the activity.

Two for one: A dual-reactive molecular probe has been devised to simultaneously measure intracellular H₂S levels and phosphatase activity. Fluorescent analysis by three-channel imaging correlation reveals that a slight deviation from the normal H₂S level leads to a sharp decrease of phosphatase activity.

Coupling therapy with silver: Under ultrahigh vacuum, aryl azides generate an elusive chemisorbed nitrenoid intermediate on Ag(111). This intermediate can transform by forming covalent σ- and π-bonds via a formal nitrene insertion into a C−H bond, dimerisation, or hydrogenation. The structure of the transformation products was elucidated by high-resolution nc-AFM imaging supported by first-principle calculations.

Core competencies: A series of novel core-expanded boron(III) subphthalocyanine analogues, namely boron(III) carbazosubphthalocyanines, have been synthesized and characterized. They represent the first examples of antiaromatic boron(III) subphthalocyanine derivatives and the smallest antiaromatic azaporphyrinoids reported thus far.

Caught in a trap: A series of new double perovskite nanocrystals Cs₂AgSb_1−yBi_yX₆ (X: Br, Cl; 0≤y≤1) is synthesized. Intrinsic self-trapping (ca. 1–2 ps) arising from giant carrier–phonon scattering and surface-defect trapping (ca. 50–100 ps) are revealed. Slow hot-carrier cooling is observed at high pump fluence.

The room-temperature phosphorescence features of a solvent-free organic liquid phosphor in air were explored. Doping of the phosphor with carbonyl guests resulted in enhanced phosphorescence, and hence a large-area paintable phosphorescent liquid composite with improved lifetime and quantum yield was developed.

Massive attack: An unprecedented radical cyclization of arylthiols with alkyne-tethered ynamides to give highly-substituted 4-arylthiopyrroles is reported. The transformation involves an unusual attack by a thiyl radical on the alkyne motif followed by cyclization with the ynamide core, which shows preferred reactivity of an alkyne over an ynamide. Density functional theory (DFT) studies support the proposed mechanism.

Lights, heat, motion! The photothermal effect has been exploited to promote fluid pumping and particle assembly using suspensions of either gold or titanium dioxide nanoparticles.

A transparent Ta₃N₅ photoanode was fabricated on GaN/Al₂O₃ substrate to develop the tandem cell for overall water splitting. The transparency of Ta₃N₅/GaN/Al₂O₃ to wavelengths longer than 600 nm allowed incoming solar light to be transmitted to a CuInSe₂ (CIS). A stand-alone tandem cell with a serially-connected dual-CIS-based cathode was constructed. This tandem cell exhibited an initial solar-to-hydrogen energy conversion efficiency of 7 %.

To eliminate, or to hydrolyze, that is the question: Structural, mechanistic, and computational studies of the abyssomicin C pathway enzyme AbyA5 establish the molecular origins of enzyme-catalyzed acetate elimination. The unexpected acetyl-esterase-like scaffold of the protein is shown to support both acetate elimination and ester hydrolysis, in a manner dictated by substrate identity.

A sticky situation: An unprecedented pure, dynamic, crystalline framework held together with weak “sticky fingers” van der Waals interactions has been developed. The fullerene-based material exhibits a remarkable single-crystal-to-single-crystal hydrogenation reaction accompanied by a color change in the visible range.

Double perovskite nanorods LaFe_xNi_1−xO₃ (LFNO NRs) with reduced diameter have been successfully created and adopted as efficient OER catalysts. The optimized LFNO NRs have proper d-band electronic structure, enabling strong binding between adsorbates and NRs, which boosts their intrinsic OER activity.

Single molybdenum atoms anchored on nitrogen-doped porous carbon were designed and synthesized for the electrocatalytic reduction of N₂ to NH₃. The catalyst exhibited high electrocatalytic activity and stability, which is attributed to its structure, conductive carbon support, high porosity, and well-dispersed single molybdenum atoms.

Growing chains: Eicosapentaenoic acid (EPA) synthase and arachidonic acid (ARA) synthase, both of which are composed of large enzyme complexes with multiple catalytic domains, utilize two types of dehydratase (DH) domains. The domain used depends on the carbon-chain length and can lead to introduction of either saturation or cis double bonds to the growing acyl chains. ACP=acyl-carrier protein, PKS=polyketide synthase.

It's just a jump to the left: Based on analysis and modification of the two sequence blocks of the natural left-handed DNA G-quadruplex Z-G4, the 12-nt sequence GTGGTGGTGGTG was identified as a minimal sequence motif for left-handed G-quadruplex formation. This motif is abundant in the human genome.

Two become one: The hybridization of metal-organic frameworks (MOFs) and nylon polymers into composites through postsynthetic polymerization is reported. This simple, scalable, bench-top approach provides a new method to design hybrid materials containing MOFs and polymers while maintaining the desired properties of both materials.

Shine a light: A semisynthetic tethered voltage indicator (STeVI1) based upon nile red is described that displays voltage sensitivity when genetically targeted to neuronal membranes. This environmentally sensitive probe allows for wash-free imaging and faithfully detects supra- and sub-threshold activity in neurons.

Full methyl jacket: A fully methylated cyclic ether 4,4,5,5-hexamethyl-1,3-dioxolane is used as an electrolyte solvent for Li–O₂ batteries. It exhibits excellent stability in the presence of superoxide or singlet oxygen because all the active α-H atoms are substituted with methyl groups. The cycling performance is 4 times greater that of conventional ether electrolytes.

On target: A nucleus-targeted organo-iridium-HSA conjugate for photodynamic therapy has been developed. Phosphorescence of a weakly emissive maleimide-functionalized Ir complex is greatly enhanced when conjugated to human serum albumin. The iridium-HSA conjugate targets the nucleus and generates ¹O₂ for photodynamic therapy upon irradiation with visible light.

Ester came early: The introduction of 2,2,2-trichloroethyl chloroformate into the electrolyte of a Li–O₂ battery leads to an outstanding rate capability (2005 mAh g⁻¹) with a remarkably decreased charge potential at a current density of 1000 mA g⁻¹. The positive effect is associated with the improved solubility of Li₂O₂ in the electrolyte and the increased diffusion rate of O₂.

Electron deficiency: The high-resolution X-ray diffraction provides all the essential information to decode even complex coloring problems in chemistry such as the disorder-induced electronic doping in ScB₂C₂. This information lead to the synthesis of the first bimetallic hetero-metallocene with lithium and scandium atoms embedded in pentagonal and heptagonal voids, respectively.

Double migration: A regioselective umpolung [1,3]-sulfonyl/[1,5]-sulfinyl migration cycloisomerization cascade of alkyne-tethered ynamides allows the construction of unconventional 4-sulfinylated pyrroles through deaurative [1,5]-sulfinylation. Density functional theory was used to study the reaction pathway.

The arylation of tri- and tetrasubstituted olefins directed by pendant carboxylic acids is reported. Quaternary carbons are established at high Fsp³ attached-ring junctures and the carboxylate directing group can be removed after the coupling. Carboxylate directivity prevents over-arylation of the new, less substituted alkene, which can be diversified in subsequent reactions.

A supramolecular strategy for fluorescent hypoxia imaging is proposed based on the host–guest complexation of azomacrocycles with commercial dyes.

An enantioconvergent synthesis of chiral cyclic allylboronates from racemic allylic bromides was achieved with a guanidine–copper catalyst. The allylboronates were obtained with high γ/α regioselectivities (up to 99:1) and enantioselectivities (up to 99 % ee) in a reaction that is believed to go through an S_N2′ borylation process.

Folding energetics of a novel class of noncanonical DNA structure, termed AGCGA-quadruplex, are reported. Compared to B-DNA and G-quadruplexes, these structures have a distinguishing thermodynamic fingerprint. Base-stacking, hydrophobic desolvation, conformational breathing, and specific binding of water molecules are the main energetic contributions driving the AGCGA-quadruplex folding.

Pd^II-catalyzed enantioselective intramolecular aminotrifluoromethoxylation of unactivated alkenes using readily accessible and stable CsOCF₃ as a trifluoromethoxide source has been developed, which affords a wide variety of enantiomerically enriched β-substituted OCF₃-containing piperidines in good yields. Introducing a sterically bulky group into pyridine-oxazoline (Pyox) ligands is crucial to increasing both reactivity and enantioselectivity.

Porous and full of potential: An unconventional polymer-derived strategy for the large-scale synthesis of high-density heteroatom-doped porous carbon materials is reported. The resulting supercapacitor shows a volumetric energy density of 36.8 Wh L⁻¹ in alkaline electrolytes, which is the highest among currently available carbon-based aqueous supercapacitors.

Single-electron process: A deaminative alkyl-Heck-type reaction and its carbonylative variant proceed through photocatalytic C−N bond activation. This process represents a significant complement to the classic palladium-catalyzed Heck reaction, and features easily available starting materials, good reaction efficiency, and mild reaction conditions. Tppy=2,4,6-triphenylpyridine.

Sound and light: Biocompatible 1D ferrous phosphide nanorods (FP NRs) have ultrasound (US) and photothermal (PT)-enhanced Fenton properties and high photothermal conversion efficiency (56.6 %) in the NIR II window, showing excellent synergistic therapeutic properties. FP NRs can also be used as a photoacoustic imaging (PAI) and magnetic resonance imaging (MRI) agent.

On the radio: A highly reactive electrophilic bromodifluoromethylthiolating reagent, α-cumyl bromodifluoromethanesulfenate, was developed and coupled with a range of (hetero)aryl boronic pinacol esters under copper catalysis. The resulting bromodifluoromethylthiolated (hetero)arenes were amenable to halogen exchange using [¹⁸F]KF/K₂₂₂. This is the first radiosynthetic route to [¹⁸F]arylSCF₃ via (hetero)aryl–SCF₃ bond construction.

Stereocontrol: E- and Z-N′-alkenyl urea derivatives of imidazolidinones may be formed selectively from enantiopure α-amino acids. Generation of their enolate derivatives in the presence of K⁺ and [18]crown-6 induces intramolecular migration of the alkenyl group from N′ to Cα. Hydrolysis of the enantiopure products under acid conditions reveals quaternary α-alkenyl amino acids.

The confinement of anthracene molecules in a metal–organic framework enables reversible yellow-to-purple photoswitching of the fluorescence emission. The photoresponse of the host–guest system strongly relies on the unique properties of the MOF host, that is, the pore geometry, connectivity, and volume as well as the structural flexibility. The solid-state photoswitching enabled the development of photopatternable, erasable, and rewritable paper.

A spoonful of sugar: A new concept for the synthesis of l-ribulose from l-arabinose was successfully established using a one-pot bioconversion consisting of engineered pyranose 2-oxidase, xylose reductase, formate dehydrogenase, and catalase. Transient kinetics in combination with molecular dynamics simulations indicate that the sugar substrate is positioned closer to the FAD N5-position in the engineered pyranose 2-oxidase than in the wild-type.

Immunomodulatory bioconjugation: An immunomodulator rapamycin was conjugated to a PEGylated protein therapeutic via a cleavable disulfide linker. This immunomodulatory bioconjugation effectively reduces anti-drug antibody (ADA) generation by inducing antigen-specific immune tolerance. The reported approach breaks the limitations of PEGylation by the proactive prevention of the generation of ADAs.

Charged up! A lithium anode with an ultra-high specific capacity (3656 mAh g⁻¹) is achieved by cross-stacking aligned carbon nanotubes into porous networks. Owing to the dendrite-free morphology and stabilized solid–electrolyte interface, lithium–oxygen batteries using this anode show a five-fold enhanced cycling stability compared to those using conventional Li anodes.

A golden π-crust: Unprecedented attractive Au–π interactions were found between a σ-coordinating C≡C moiety and neighboring gold atoms of diacetylene-modified Au₈ clusters. The interaction was observed specifically for the diacetylenic ligands, and not found in the mono-acetylenic analogues, indicating the uniqueness of the diacetylenic ligands.

Pop around: Reported herein is a precoordination/solvothermal polymerization strategy to fabricate a stable atomically dispersed mononuclear Pd-metalized N-heterocyclic carbene doped porous organic polymer catalyst (Pd@POP). This Heck reaction of electronically unbiased alkenes is the first to be catalyzed by a recyclable catalyst (Pd@POP-9) with unprecedented catalytic activity and regioselectivity.

Quaternary center exchange: Fully substituted carbon centers bearing a carboxylate moiety can engage in decarboxylative cross-couplings with aryl zinc reagents under nickel catalysis, leaving in their wake an arene group.

Combining oxygen and fluorine: α-Oxygen-functionalized amides were employed as enolate surrogates in a direct catalytic aldol coupling with α-fluorinated ketones. Because of the likely involvement of open transition states, both syn- and anti-aldol adducts can be accessed with high enantioselectivity by judicious choice of the chiral ligands.

Surprise shift: An efficient route to β-amino silyl enol ethers by an α-alkenyl addition/proton shift sequence from silyl enol ethers to ketimines has been developed. Good enantioselectivities with a broad substrate scope were achieved using chiral N,N′-dioxide/Zn^II complexes. Deuterium-labeling studies suggest that a key proton shift is involved in this reaction.

On the double: A scalable, one-pot, enantioselective catalytic synthesis of 2-pyrazolines from beta-substituted enones and hydrazines is described. The method uses a readily prepared cinchona-derived bifunctional catalyst. Pivoting on a two-stage catalytic Michael addition/condensation strategy, the use of an aldehyde to generate a hydrazone derivative of the hydrazine is key for curtailing background reactivity and tuning the catalyst-controlled enantioselectivity.

Going for a ′SPIN′: The enantioselective synthesis of a series of 3,3′-diarylated 1,1′-spirobiindane-7,7′-diols (3,3′-diaryl-SPINOLs) was developed using a sequential Rh-catalyzed twofold asymmetric conjugate arylation/BF₃-promoted diastereoselective spirocyclization. Some phosphoramidite ligands were prepared from the 3,3′-Ph-SPINOL and applied to several catalytic asymmetric reactions, and the 3,3′-diarylated ligands showed higher enantioselectivities than the privileged nonsubstituted ligands.

Mono- or bis-homologation was realized with lithium halocarbenoids for the assembly of trifluoromethyl aziridines. Trifluoroacetimidoyl chlorides act as electrophilic platforms, enabling the addition of either one or two homologating elements. Use of two different carbenoids leads to fluoromethyl analogues in which the first nucleophile is employed for constructing the cycle and the second one for decorating the resulting molecular architecture.

The incredible bulk: A new nickel(II) pre-catalyst featuring the PhPAd-DalPhos ancillary ligand is effective for the challenging cross-coupling of sterically hindered primary alkylamines and (hetero)aryl halides under mild conditions.

The first asymmetric total synthesis of the meroterpenoid (−)-merochlorin A is described, leading to the assignment of the previously undetermined absolute configuration.

Forming a partnership: The cooperative catalysis of copper, silver, and a Brønsted acid is presented as a new strategy for olefin functionalization. The direct catalytic carbohydroxylation of styrenes with allylic alcohols proceeds smoothly with excellent regioselectivity under mild reaction conditions.

In equal measure: A cobalt/diphosphine catalyst promotes a selective [2+2] cycloaddition reaction between an alkyne and an allene, affording a 3-alkylidenecyclobutene with high regioselectivity. The reaction tolerates various internal alkynes, and mono- and disubstituted allenes with different functional groups, and can be achieved using a near equimolar mixture of the unsaturated reactants.

Lanthanum hydride, generated by reaction of lanthanum alkyl and pinacolborane, is a catalyst for ester and epoxide hydroboration. Yet, lanthanum hydride reacts with ketones by insertion, whereas pinacolborane is required for ester conversion.

From a distance: Chemoselective trifluoromethylation of unactivated C(sp³)−H bonds distal to the functional group was achieved under mild, copper-catalyzed conditions. A radical mechanism involving 1,5-hydrogen atom transfer of N-radicals followed by CF₃-transfer from Cu^II−CF₃ complexes to the thus formed alkyl radicals is proposed.

Hand in hand: A chiral Cp^xRh^III catalyst system generated from a Cp^xRh^I(cod) precatalyst and bis(o-toluoyl) peroxide engages in aryl and alkenyl C−H activation/ring-opening sequences between ketoxime ethers and 2,3-diazabicyclo[2.2.1]hept-5-enes. The transformation provides densely functionalized chiral cyclopentenylamines in excellent yields and high enantioselectivities.

Thin films: The effect of compositional constraints on the synthesis of highly b-oriented MFI zeolite films on stainless-steel plates using secondary growth solutions, free of organic template, was investigated. The number of twin crystals can be significantly reduced, and even eliminated, simply by restricting the pH value of the secondary growth solutions to the narrow range of 11.1–11.3.