Catalyst design: This Minireview summarizes the recent progress in early transition metal polymerization catalyst development, categorized by the catalytic metal complex and polar comonomer identity. Advances in the mechanistic understanding of these polymerizations are discussed, focusing on critical challenges and strategies that mitigate them.

The CO₂ electroreduction reaction has recently gained in popularity. Cu is still the only monometallic catalyst that can effectively produce interesting molecules, such as hydrocarbons and alcohols. Many breakthroughs have been on the so-called structure–activity/selectivity relationships. However, the stability of Cu-based electrodes and nanoscale degradation mechanisms are still in their infancy.

Bindungsbildung im angeregten Zustand: Linear zweifach koordinierte Gold(I)-Komplexe bilden durch seitlich orientierte aurophile Wechselwirkungen Aggregate aus, deren schwache Au-Au-Kontakte durch UV-Bestrahlung verstärkt werden, ersichtlich an einer Verkürzung des Au-Au-Abstands und veränderter Absorptions- und Emissions-Charakteristika. Die veränderten Redoxpotentiale machen die [Au^I−Au^I]*-Excimere zu reaktiven Intermediaten für die Photoredoxkatalyse.

A migratory insertion mechanism has been proposed for the polymerization of diphenylacetylenes by a classic metathesis catalytic system composed of tungsten(VI) chloride (WCl₆ or WOCl₄) and Ph₄Sn. The polymerization is initiated by addition of a phenyl group coming from Ph₄Sn to diphenylacetylene monomers and has two possible termination processes.

Coupled complex: A novel crystalline proton–electron coupling system was developed using an iron(II) hydrazone complex. The complex exhibits a thermally and photoinduced proton-transfer-coupled spin transition. The intermediate phase has two types of iron(II) complexes with distinct spin states and proton positions. The proton transfer in one of the two ligands changes the direction and magnitude of the molecular dipole moment.

Haruspex is a new tool to identify secondary structure and RNA/DNA in cryo-EM reconstruction maps. It uses a neural network which has been trained on a carefully curated set of 293 experimentally derived reconstructions and can be straightforwardly applied to newly reconstructed maps to support model building and validation.

All in one: Highly efficient multisegment native chemical ligation (NCL) has been developed by exploiting the Fmoc group to temporarily mask the N-terminal Cys of the peptide thioester fragments. Fmoc removal and NCL are achieved in the same reaction mixture through pH adjustments in presence of 20 % piperidine. The simplicity and inherent robustness of this method make it an attractive approach for the high-yielding total synthesis of proteins.

A photoelectrochemical reactor comprised of a III-V-based photovoltaic cell integrated with nickel foil as an O₂ evolving catalyst achieves a solar-to-hydrogen (STH) efficiency of 18.3 % at low light concentration without optical lenses. An STH efficiency of 13 % is attained at high light concentration with optical lenses. A 100 hour test at 100–200 suns showed no degradation or deviation from product stoichiometry (H₂/O₂=2).

A new, universal ¹⁹F broadband relaxation-edited NMR experiment enables fast screening of the entire drug-relevant fluorine chemical shift range for distinct hit molecules in a single measurement. It further facilitates the efficient generation and evaluation of large, chemically diverse compound libraries and expedites the ligandability assessment of any macromolecular target.

Photocatalytic syngas production: The use of homogeneous molecular iron catalysts combined with a CdS nanorods (NRs) semiconductor creates a novel photocatalytic system for direct conversion of formic acid to syngas at room temperature and atmospheric pressure. These catalysts demonstrate remarkable enhancement in CO evolution with robust stability.

Fine mechanics: A systematic experimental and computational study explains why tiny structural changes in the extremities of a molecular axle can allow or prevent its insertion in the cavity of a macrocycle. These results provide guidelines to design interlocked molecules with predetermined dynamic features, that can be used to make nanostructured machines, motors and materials.

That′s dope! The energy cost of moving an electron from sulfur to its neighboring metal atoms can predict the trend in hydrogen-binding strengths in MoS₂ and its doped variants. An electronic-structure-based descriptor for the hydrogen-binding strength allows to understand these trends: Δ_dp, the local interband energy separation between the lowest empty d-states on the dopant metal atoms and occupied p-states on sulfur.

DNA technology was used to precisely regulate both lateral and vertical positioning of T cell activation ligands on the membrane of red blood cells to better mimic natural antigen presenting cells, thereby providing a tool for T cell activation studies and enhanced adoptive immunotherapy.

Round round get around: A highly efficient metal-catalyzed tandem cycloaddition reaction enables benzannulation to access cyclopolyarene nanorings of varied sizes from poly(arylene-butadiynylene) macrocyclic precursors. Unique Möbius topology is manifested by the cyclopolyarene nanorings composed of an odd number of repeat units, whereas cylindrical tubular structures with radial conjugation are formed with an even number of repeat units.

CH–π interactions are crucial determinants for the affinity of arguably every drug molecule. PI by NMR can differentiate the strength of protein–ligand CH–π interactions in solution. By combining selective amino-acid side-chain labeling with ¹H-¹³C NMR, CH–π interactions can be identified based solely on ¹H chemical shift values. This information serves as a proxy for the strength of each individual CH–π interaction.

1,2-Difluorobenzene serves as an electrolyte diluent to realize the high-concentration effect in lithium metal batteries even at a bulk salt concentration near 2 m. The incorporation of this diluent also induces an anion-associated lithium solvation structure to passivate lithium metal with a LiF-rich solid-electrolyte-interphase (SEI) layer, thereby resulting in superior cyclability.

No need to be sour: CO₂/CH₄ and H₂S/CH₄ separation performance of glassy polyimide membranes can be tailored by finely tuning the DAM:DABA ratio in the 6FDA-DAM:DABA polyimide backbone. This facile tunability is attractive for their applications for challenging sour gas separation (that is, methane contaminated with undesirable acid gases (CO₂ and H₂S)) across a spectrum of feed compositions.

Chain walking makes the difference: The utilization of chain-walking features can enable new polymerization strategies (gas-phase polymerization and heterogenized slurry-phase polymerization) using existing late-transition-metal-based olefin polymerization catalysts.

A forgotten curiosity: Ixene, a compound that was previously named but never prepared, and its BN-doped derivative (B₂N₂-ixene) were synthesized in two steps from simple intermediates. The effect of BN-doping, or substitution of carbon–carbon bonds with isoelectronic boron–nitrogen bonds, was elucidated both experimentally and theoretically.

Crystal clear: Reported here is the synthesis of a centimeter-sized AA′_n−1M_nX_3n+1 type perovskite, BDAPbI₄ (BDA=NH₃C₄H₈NH₃), single crystal and its charge-transport properties under X-ray excitation. The crystal shows a staggered configuration of the [PbI₆]⁴⁻ layers, a band gap of 2.37 eV, and a low trap density of 3.1×10⁹ cm⁻³. These crystals are promising candidates for the next generation of optoelectronic devices.

The mechanism of aggregation-induced emission is revealed by monitoring real time structural evolution and dynamics of the electronic excited state. The formation of Woodward–Hoffmann cyclic intermediates as nonradiative relaxation pathway is observed in dilute solutions of tetraphenylethylene upon ultraviolet excitation. In solid state, the electronic excitation is preserved, and the molecule fluoresces efficiently.

Evolution of activity: A facile and high-yield synthesis of para-substituted tris(2-pyridylmethyl)amine-based ligands is presented. Copper complexes with these ligands exhibit very high activity in atom transfer radical polymerization.

Give and take: Operando Raman spectroscopy in combination with in situ XRD and thermal analysis was applied to study a Mn-Na₂WO₄/SiO₂ catalyst at work during the oxidative coupling of methane. Melting of Na₂WO₄ and Mn₇SiO₁₂-MnWO₄ redox chemistry occur simultaneously, thereby enabling the transient release and storage of active sodium oxide species. Coupling of these processes is essential to avoid catalyst deactivation.

Novel organic lasers were fashioned from large, aggregation-free polycyclic aromatic hydrocarbons (PAHs. Several new perylene-based PAHs were prepared that show perylene-like electronic properties with moderate fluorescence quantum yields. Two of them show amplified spontaneous emission, and solution-processed distributed feedback lasers were successfully fabricated.

It's electric: An advanced dual-additive electrolyte containing a unique solvation structure comprising tris(pentafluorophenyl)-based additives and LiNO₃ in a carbonate-based electrolyte is reported. It can generate a robust outer Li₂O solid electrolyte interface (SEI) and a F- and B-containing conformal cathode electrolyte interphase (CEI), thus realizing a stable cell operation when E/C and the N/P ratio decrease to 3.4 g Ah⁻¹ and 2.28, respectively.

Down to the nanowire: A convenient, rapid, and robust capillary-assisted solution printing (CASP) strategy, which combines nanochannel-enabled, capillary-guided assembly with moving substrate-facilitated printing, yields a perovskite nanowire array with excellent optoelectronic properties for photodetectors.

Methyltransferase enzymes (MTs) selectively deliver methyl substituents to an array of molecules, thereby controlling gene expression or modulating the bioactivity of therapeutically important natural products. A MT was engineered for selective carboxy(m)ethylation to give an orthogonal MT that was combined with the SAM-derivatising enzyme CmoA to create new carboxymethylation pathways.

Intracellular delivery: a new combinatorial library of cholesteryl-based and reduction-responsive lipidoid nanoparticles can deliver genome engineering protein and mRNA molecules in vitro and in vivo. Using adult Ai14 mouse model, successful Cre-mediated gene recombination events were observed in skeletal muscle, brain, lung, and spleen through the local and systemic administrations.

One for the books: An amine-bearing DNA-encoded chemical library (DEL) can be converted into a DNA-encoded dynamic library (DEDL) and subjected to selection against biological targets for inhibitor discovery. Full ligand structures can be obtained without the need for fragment linking.

Sensing in close quarters: A nucleic acid-based electrochemical platform able to measure levels of immunoglobulins of type G and E (IgG and IgE) directly in blood serum and other bodily fluids was developed. The antibody detection exploits effective molarity effects that are induced by the spatial confinement of electrochemically active DNA-based sensing modules at the nanoscale.

Less is more: Toehold-mediated strand displacement has been used to produce dynamic DNA nanostructures and networks; however, the complexity of sequence design dramatically increases as the size and complexity of the DNA network increases. Fuzzy strand displacement allows a single input strand to displace multiple substrate strands and multiple input strands to displace a single substrate strand, reducing the complexity of DNA-sequence design.

Catalytic strategies for the α-C−H functionalisation of primary amines are a major challenge in organic synthesis. A photocatalytic protocol for the α-C−H alkylation of unprotected primary amines that is amenable to the direct synthesis of α-tertiary primary amines is reported. This process is readily scalable in continuous flow to provide access to decagram quantities of valuable γ-lactams and azaspirocycles, for application in drug discovery.

Metalation site prediction: The use of simple pK_a calculations allowed a reliable prediction of metalation sites in various heterocycles, arenes, olefins, and alkanes, employing the mild base TMPZnCl⋅LiCl. Using this predictive model, also unexplored N-heterocycles were investigated, and the obtained deprotonation sites rationalized readily.

A blinking mesoporous TiO_2−x is composed of small, crystalline, vacancy-rich anatase nanoparticles. It shows unique optical, thermal, electronic, and photocatalytic properties. The nanoparticles continuously light up and fade away for an extended period of time under an electron beam. They also show long-lived charge carriers (trapped electrons and holes) at room temperature in the dark, even long (30 min) after UV irradiation.

The big bucks: A wide range of fullerenes (buckyballs; C₃₀–C₁₁₄) and their building blocks (buckybowls with a stoichiometry of C_10xH₁₀) were detected in heavy crude oil by ultrahigh-resolution mass spectrometry. Structural findings are supported by high-level calculations at the DLPNO-CCSD(T) level of theory, revealing for the first time the presence of fullerenes in low-energy fossil materials on a molecular level.

Atomically thin bismuthene with excellent electrocatalytic CO₂ reduction performance is obtained from ultrathin metal–organic layers by an in situ electrochemical transformation process. A reaction route involving HCO₃⁻ for formate production is revealed.

All in one: Direct olefin diamination with alkylamines was achieved by using a photoinduced radical-to-polar crossover strategy. This approach enables the programmable and sequential addition of complex amine building blocks across olefins in a single chemical transformation. This operationally simple process has broad functional-group compatibility and enables the use of advanced building blocks for the preparation of drug-like small molecules.

A cluster of motile and mature sperm previously immobilized on the BSA-HA microflake is transported by a magnetically-driven microhelix, which delivers the sperm-loaded microflake close to the area of interest. Due to the presence of local proteases, the microflake is then hydrolyzed allowing the sperm release to finally reach the target location.

Logic gates that read DNA molecules and return plasmonic chiroptical signals are presented. They are achieved on a DNA-based platform that can direct the conformation of two gold nanorods. With delicate designs, the logic gates can operate in an adaptive manner, namely, they perform as AND gates at body temperature while as OR gates at cold storage temperature.

Triplet materials are designed by introducing heavy atoms to enhance spin–orbit coupling or constructing donor and acceptor units with a twisted conformation to reduce ΔE_ST. However, the twisted materials have not been applied in solar cells due to weak absorption and low charge-transport mobilities. Now two nonplanar acceptors with large π-conjugated core were constructed that achieved over 15 % efficiency.

Umweltschonende Polymerisation: Der Anwendungsbereich der hydrothermalen Polymerisation wurde erweitert: Pyrronpolymere und Polybenzimidazole können jetzt in nichts anderem als in hochtemperiertem Wasser durch eine einfache einstufige Synthese erzeugt werden.

Die angeregten Triplett-Zustände in einem neuen heterogenen Triplett-Sensibilisator, Kalium-Polyheptazinimid (K-PHI), können genutzt werden, um eine Kaskade von Energieübertragungsreaktionen auszulösen und z. B. Singulett-Sauerstoff (¹O₂), als Ausgangspunkt für die Synthese von N-reichen Heterozyklen, zu sensibilisieren. Auf diese Weise werden Aldoxime unter Bestrahlung mit sichtbarem Licht in Oxadiazole-1,2,4 umgewandelt.

Eine Iod(I)/Iod(III)-katalysierte Strategie für den Zugang zu enantiomerenangereicherten 3-Fluorchromanen wird gezeigt. Die In-situ-Erzeugung von ArIF₂ ermöglicht die direkte Fluorzyklisierung von Allylphenylethern, um neue Molekülgerüste aufzubauen, die den stereoelektronischen gauche-Effekt manifestieren. Mechanistische Untersuchungen mit deuterierten Substraten bestätigen einen stereospezifischen Prozess, der mit dem Reaktionsweg des Typs II_inv übereinstimmt.

Die elektrooxidative C-H-Olefinierung von Amiden wird durch Rhodiumkatalyse ermöglicht. Die Olefinierung elektronenarmer Benzamide wurde unter elektrochemischen Bedingungen entwickelt und verläuft nach einem dehydrierenden Mechanismus mit H₂ als einzigem Koppelprodukt. Die stöchiometrische Verwendung von chemischen Oxidationsmitteln wird dabei vermieden.

Lockdown von Azobenzol: Photoisomerisierbare Moleküle wie Azobenzol wandeln Licht direkt in chemische Energie, jedoch mit einer geringen Energieeffizienz um. Durch systematische Reduktion der konformationellen Flexibilität von Azobenzol und somit der Verhinderung von unproduktiven Reaktionspfaden wurde die Energieumwandlungseffizienz von 1.4 % auf 18.1 % erhöht. Dies ist die höchste bisher bekannte Effizienz aller photochromen Verbindungen.

Stabile homonukleare Tetrasila-1,3-cyclobutandiyl-Analoga wurden aus den Gleichgewichtsreaktionen eines Cyclotrisilens und gesättigter N-heterocyclischer Silylene (c-[(CR₂CH₂)(NtBu)₂]Si: (R=H, Me)) erhalten. Festkörperstrukturen zeigen im Wesentlichen planare viergliedrige Si₄-Ringsysteme. Trotz der großen Entfernung zwischen den formalen Radikalzentren deuten Berechnungen auf eine nicht unterstützte π-Bindung.

Der Traum von einer anionischen Version der Kation-π-katalysierten Steroidcyclisierung wird mit den Epoxidöffnungs-Ethercyclisierungen von Oligomeren realisiert. Verglichen mit konventionellen Katalysatoren erweist sich die Anion-π-Autokatalyse als schnell (Reaktionsbeschleunigung >10⁴ m⁻¹) und mechanistisch ausschlaggebend (Goldilocks-Profile) und bietet faszinierende Perspektiven.

A luminescent cocrystal exhibits reversible luminescent switching, responding to THF-vapor/thermal stimuli and mechanical grinding. The crystal-to-crystal phase transition between two different cocrystal polymorphs under the external stimuli was demonstrated, enabling an in-depth understanding of the luminescent switching of organic luminescent materials.

Cooking with gas: CO₂ gas and frustrated Lewis pair monomers can polymerize to form vesicles. Changing the gas used results in the formation of vesicles with distinct components, architectures, and morphologies. This introduces the use of gases to form nanomaterials and could be used to recycle industrial waste gases.

A Li metal anode working at 90 °C is demonstrated in a thermotolerant liquid electrolyte. The anode undergoes 100 cycles in a Li|LiFePO₄ battery at 90 °C (10 cycles in a practical carbonate electrolyte). High operation temperature promotes independent and incomplete decomposition of Li salts and solvents to form a distinctive solid electrolyte interphase.

The d-peptide ^DTBP-3 was identified, which could effectively block TIGIT/PVR interaction. ^DTBP-3 could inhibit tumor growth and metastasis in anti-PD-1 resistant tumor model and could serve as a potential candidate for cancer immunotherapy.

Getting into shape: The role of chloride, nitrate, and alkali ions during metal-oxide crystallization via molten salt routes has been thoroughly explored. It is shown that various ion combinations direct the NiO crystal morphology with nitrates acting as oxygen donors. Findings reveal the generation of unique high-index {311} facets in media containing Cl⁻ and K⁺ ions.

Carbon nanobasket: A new cyclophane bearing two units of heptagon-containing hexa-peri-hexabenzocoronene is presented. The macrocycle offers an unusual aromatic calix-shaped cavity able to interact with fullerenes. The selective binding of C₇₀ over C₆₀ is demonstrated.

A liquid crystalline elastomer strip can expand in both length and width on cooling and shrink along the two directions on heating over order–disorder phase transition.

In-situ reversible click reaction based on the rapid condensation of boronic acid functionalities with salicylhydroxamates is used to prepare polymer–drug conjugates, which form nanoassemblies that can undergo a stimuli-induced release of pristine drugs.

In control: Solute molecules are assembled in the microchannel between solvent crystal grains driven by solvent recrystallization. Benefitting from separate and adjustable assembly kinetics and thermodynamics of the solvent recrystallization, various molecules can be assembled into monodisperse amorphous and crystalline particles with precisely controlled sizes, down to that of single atoms.

A reductive approach: A diselenide-based probe for the detection of thioredoxin reductase 1 (TrxR1) was designed and synthesized. The non-fluorescent probe switched on in the presence of TrxR1 and had minimal interference from other biological reducing species. The diselenide probe was successfully used in imaging TrxR1 in human lung cancer cells and showed greater fluorescence compared to a disulfide-based analogue.

I got the Nile blues: Mesoporous silica nanoparticles loaded with Nile blue and capped with a galacto-hexasaccharide are used for in vivo imaging of cellular senescence. Fluorescence dye emission is quenched inside nanoparticles, yet a remarkable fluorescence is observed upon cap hydrolysis by β-galactosidase. The probe detects cellular senescence in vitro and in vivo in palbociclib-treated BALB/cByJ mice bearing breast tumors.

Light triggers: Photoinduced electrochemiluminescence (PECL) can be induced at BiVO₄ photoanodes in an aqueous electrolyte containing a luminol derivative (L-012), at a record potential of −0.4 V. Here, the incident light simultaneously triggers L-012 fluorescence and PECL. The latter process considerably amplifies the luminescence and the potential control allows fine tuning of the overall luminescence.

A Covalent PET probe: An ¹⁸F-labeled, activity-based small molecule probe, [¹⁸F]JW199, potently and selectively targets NCEH1 in live cells and displays rapid, NCEH1-dependent accumulation in mouse tissues and tumor xenografts.

3D p-POP! A 3D π-conjugated porous organic polymer incorporating in situ formed pentacene linkers was synthesized through a catalyst-free Diels–Alder cycloaddition polymerization and an acid-promoted aromatization reaction. The resulting polymer shows high electrical conductivity and is the first member of a class of permanently porous 3D organic semiconductors.

The hypervalent iodine reagent PIDA in combination with a nucleophilic amine (DABCO or pyridine) induces α-functionalization of enones with three different nucleophiles. The reaction is proposed to proceed through the umpolung of Morita–Baylis–Hillman type intermediates. The proposed mechanism is supported by spectroscopic studies that details the conversion of several reaction intermediates into products.

Hetero-liposomes with a structural composition similar to that of eukaryotic cells were prepared by constructing transmembrane peptide frames that mimicked the cell cytoskeleton structure. The conformation and transmembrane mode of the peptides played dominant roles during the frame-guided assembly (FGA) process. FGA liposomes were formed with excellent stability and could be utilized as a drug delivery platform.

All-polymer solar cells (all-PSCs) are composed of polymer donors and acceptors, which hold potentially superior morphological stability and mechanical flexibility. In this work, a new random ternary copolymerization strategy was adopted to synthesize new polymer acceptors with high performance. The all-PSCs based on the new polymer acceptor shows high power conversion efficiency of over 12.5 % and high photostability capable of withstanding long-term illumination stress.

The aromatic diamine 1,10-phenanthroline acts as a framework-bound template for the large-pore aluminophosphate zeotype STA-28 and can be used to introduce Fe for Al at a single crystallographic site, as verified by Rietveld refinement and annular dark field scanning transmission electron microscopy. Removal of the template leaves a crystalline microporous solid with accessible iron cations.

Disorderly conduct: A crystal-engineering strategy has been introduced to narrow the band gap of benchmark double perovskite Cs₂AgBiBr₆. The band gap of Cs₂AgBiBr₆ crystals can be reduced from 1.98 eV to 1.72 eV, reaching the smallest reported band gap for Cs₂AgBiBr₆ under ambient conditions. DFT calculations indicate that Ag–Bi disorder in the crystal structure could lead to band-gap narrowing.

Ringing the changes: A practically useful method for the formation of the highly oxygenated bicyclo[3.2.1]octane ring system through Mn(OAc)₃-mediated radical cyclization of alkynyl ketones was developed, which opens up a new avenue for the total synthesis of a number of highly oxidized diterpenoids. Application of this method enabled the first total synthesis of the ent-kaurene diterpenoid(−)-glaucocalyxin A.

View to a kill: Emissive metallacycle-crosslinked supramolecular networks with hexagonal metallacycles as their crosslinks were developed. These networks were employed for bacterial imaging and killing based on the properties of the introduced metallacycles.

Sweet dreams are made of this: A highly stereoselective electro-2-deoxyglycosylation from glycals was developed. This method features excellent stereoselectivity, scope, and functional-group tolerance, and can also be applied to the modification of a wide range of natural products and drugs. Furthermore, a scalable synthesis of glycosylated podophyllotoxin and a one-pot trisaccharide synthesis through iterative electroglycosylations were achieved.

Radio-photoluminescence in MOFs: The first metal–organic framework (MOF) to display radio-photoluminescence (RPL) may lead to a new generation of RPL dosimeters showing advantages in terms of detection sensitivity, detection range, reusability, stability, and energy threshold over the existing commercial materials.

A diiron bridging nitride complex supported by a geometrically flexible, redox-active macrocycle was synthesized and characterized by X-ray crystallography and Mössbauer spectroscopy. Treatment of the electrophilic nitride with PhSH afforded NH₃ in high yield through a reaction that engages the redox-activity of the ligand during proton-coupled electron transfer followed by protonolysis.

Cycles and chains: The first perfluorinated auracycles and complexes containing Au(CF₂)_nAu chains are prepared. LAu(CF₂)₄AuL complexes adopt folded conformations stabilized by an aurophilic interaction depending on the auxiliary ligand L. The study of their dynamic behaviour in solution has allowed the energy associated with an aurophilic interaction to be determined.

Absolution by SERS: A surface-enhanced Raman scattering chiral anisotropy effect is presented that combines chiral discrimination and surface Raman scattering enhancement on chiral nanostructured Au films. It is applied in the normal Raman scattering system to identify the absolute configuration and composition of enantiomers, overcoming disadvantages of polarimeter systems and chromatography.

Focussing on one step: The transfer of adsorbed hydroxyl (OH_ad + e⁻⇄ OH⁻) has been isolated and identified as a critical step in the alkaline hydrogen evolution reaction on Ni/Co-modified MoSe₂ model catalysts.

The straightforward π-extension of unfunctionalized heterobiaryl compounds is achieved by electrochemical oxidative [4+2] annulation reactions with alkynes or alkenes. The anodic oxidation of heterobiaryl compounds generates heteroarene radical cations, and the selective nucleophilic attack proceeds with good regioselectivity under mild conditions.

A cascade reaction has been designed for the synthesis of spirocyclic pyrrolines from nitrones and arynes. A key feature of this transformation is an unusual dearomative [3,3′]-sigmatropic rearrangement of a heterocyclic intermediate that results in a spirocyclization. This modular approach provides access to three-dimensionally-defined pyrrolines and pyrrolidines with opportunities for divergent derivatization.

Come full circle: A highly chemoselective cobaloxime-catalyzed acceptorless dehydrogenative cyclization of o-teraryls was developed. Due to the acid- and oxidant-free conditions, diverse substrates with various electronic properties and sensitive functional groups, including electron-poor arenes and electron-rich heterocycles, are tolerated.

An asymmetric Shono-type oxidative cross-coupling to give C1-alkynylated tetrahydroisoquinolines with good to excellent enantioselectivity was developed by merging copper catalysis and electrochemistry. The use of TEMPO as a co-catalytic redox mediator is crucial for oxidizing a tetrahydroisoquinoline to an iminium ion species and for decreasing the oxidation potential of the reaction.

To bend or not to bend: Photoelectron spectroscopy and ab-initio calculations show that IrB₂O⁻ has a bent (⁻OB)Ir≡B structure and ReB₂O⁻ has a linear structure, [Re≡B−B≡O]⁻. The latter is the first example of a transition-metal borylyne complex.