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Polyhydroxyalkanoates are potential substitutes for non-degradable polyolefin plastics. Now, it has been shown that structurally related methylated polyhydroxybutyrates, synthesized from carbon monoxide and 2-butenes, can provide a full suite of polyolefin-like polymers. These materials can be recycled or upcycled, and their properties can be easily tuned by varying the cis/trans ratio of the starting materials.

Knots reduce the tensile strength of macroscopic threads and fibres. Now it has been shown that the presence of a well-defined overhand knot in a polymer chain can substantially increase the rate of scission of the polymer under tension, as deformation of the polymer backbone induced by the tightening knot activates otherwise unreactive covalent bonds.

Phenols and their derivatives are ubiquitous in nature and important within the chemical industry. Their properties are linked to their substitution patterns, but meta-isomers are underrepresented due to the difficulty of their synthesis. Now we address this challenge by describing a 1,2-transposition of phenols that enables a formal para- to meta-isomerization.

Enantioconvergent reactions convert both enantiomers of a racemic starting material into a single enantioenriched product. All currently known enantioconvergent processes necessitate the loss or partial loss of the racemic substrate’s stereochemical information. Now, an alternative approach has been developed that proceeds with full retention of the racemic substrate’s configuration.

Chiral 1,2-benzazaborines are promising isosteres of naphthalene, but rarely explored due to the lack of efficient synthetic methods. Now, the copper-catalysed enantioselective hydroboration of alkenes with 1,2-benzazaborines has been developed, providing a general platform for the atom-economic and efficient construction of diverse chiral 1,2-benzazaborine compounds bearing a 2-carbon-stereogenic centre or allene skeleton.

Fusicoccane diterpenoids are complex natural products with intricate tricyclic skeletons and intriguing biological activities. Now a chemoenzymatic strategy has been developed for modularly synthesizing a number of compounds from the family. This approach combines de novo skeletal construction and hybrid C–H oxidations, allowing the synthesis of ten different natural products.

Indole alkaloids extracted from closely related fungi lead to questions about how their biochemical pathways have evolved

Chiral sulfur pharmacophores are crucial in drug discovery, but the controlled synthesis of sulfinamides with stereogenic-at-sulfur(IV) centres is a long-standing challenge. Now a method for the catalytic asymmetric synthesis of sulfinamides and sulfinate esters has been developed that features the acyl transfer sulfinylation of diverse nucleophiles, including aromatic amines and alcohols, using chiral 4-arylpyridine N-oxides as catalysts.

The number of known high-oxidation-state transuranic compounds remains limited, and these typically feature high coordination numbers and/or multiply-bonded donor atoms. Now, a tetrahedral, pentavalent neptunium complex supported by four monoanionic ligands has been isolated and characterized. This complex is stable in the solid state and undergoes a proton-coupled electron transfer reaction in solution.

The systemic discovery of metal–small-molecule complexes from biological samples is a difficult challenge. Now, a method based on liquid chromatography and native electrospray ionization mass spectrometry has been developed. The approach uses post-column pH adjustment and metal infusion combined with ion identity molecular networking, and a rule-based informatics workflow, to interrogate small-molecule–metal binding.

The construction of analogues of natural gap junctions would provide a bottom–up strategy for building intercellular communication pathways for synthetic cells. Now artificial intercellular gap junctions have been prepared from unimolecular tubular channels by mimicking the hydrophobic–hydrophilic–hydrophobic triblock structure of natural junction channels.

α-Amino acids possessing β-stereocentres are difficult to synthesize. Now, an iridium-catalysed protocol allows the direct upconversion of simple alkenes and glycine derivatives to give β-substituted α-amino acids with exceptional levels of regio- and stereocontrol. The reaction design is based on exploiting the native directing ability of a glycine-derived N–H unit to facilitate enolization of the adjacent carbonyl.

Evolution separates complex modern enzymes from their hypothetical simpler early ancestors, which raises the question of how unevolved sequences can develop new functions. Here a library of non-natural protein sequences was subjected to ultrahigh-throughput screens in microfluidic droplets, leading to the isolation of a phosphodiesterase enzyme capable of hydrolysing the biological second messenger, cyclic AMP.

Two-dimensional covalent organic frameworks (2D COFs) enable the construction of bespoke functional materials, but designing dynamic 2D COFs is challenging. Now it has been shown that perylene-diimide-based COFs can open and close their pores upon uptake or removal of guests, while fully retaining their crystalline long-range order. Moreover, the variable COF geometry enables stimuli-responsive optoelectronic properties.

A robust organometallic platform is developed for stoichiometric cross-couplings of common aryl and alkyl electrophiles under a single set of conditions. Inexpensive and persistent organonickel complexes are prepared by electrolysis and implemented in the diversification of drug-like molecules with high reliability from a diverse set of alkyl precursors.

Natural products populate areas of chemical space not occupied by average synthetic molecules. Here, an analysis of more than 180,000 natural product structures results in a library of 2,000 natural-product-derived fragments, which resemble the properties of the natural products themselves and give access to novel inhibitor chemotypes.

Despite their intriguing photochemical activities, natural photoenzymes have not yet been repurposed for new-to-nature activities. Now, by leveraging the strongly oxidizing excited-state flavoquinone cofactor, fatty acid photodecarboxylases were engineered to catalyse unnatural decarboxylative radical cyclization with excellent chemo-, enantio- and diastereoselectivities.

Overcrowded alkene-derived molecular motors convert light and heat into chirality-directed unidirectional rotary motion, but the efficiency of their photochemical isomerization remains limited. Now formylation of the motor core has been shown to boost all aspects of motor photochemistry by improving photochemical efficiency, diminishing competing processes and redshifting absorption.

Advances in the development of cytoskeletal-like materials with modular structures and mechanics are pivotal for the engineering of synthetic cells. Now actin-mimetic supramolecular peptide networks have been designed using programmable peptide–DNA crosslinkers, giving rise to tunable tactoid-shaped bundles and mechanical properties that control spatial localization, the diffusion of payloads and shape changes within artificial cells.

The selective synthesis of ultrahigh-molar-mass (UHMM) cyclic polymers from direct polymerization is elusive. Using a chemically recyclable polythioester as a model, it has now been shown that a common superbase mediates living linear-chain growth, followed by proton-triggered linear-to-cyclic topological transformation, producing UHMM cyclic polymers with a narrow dispersity.

A previous investigation of the anti-aromatic dianion of [18]annulene concluded that it consists of a mixture of two isomers. Now it has been shown that this dianion exists as a single isomer, with a different geometry from neutral [18]annulene, and that it can be reduced further to an aromatic tetraanion.

John Steele and Stephen Wallace discuss recent advances in the chemical and biotechnological synthesis of the prolific platform chemical adipic acid.

Although metal-free catalysts, featuring defined active sites, represent alternatives to scarce or problematic metals, metal-free compounds rarely show activities as promising as metal-based materials. Now deprotonated 2-thiolimidazole is shown to serve as a metal-free electrocatalyst for selective acetylene hydrogenation and achieves competitive performances with metal-based catalysts.

The flow of energy in Earth's primary light harvesters — photosynthetic pigment–protein complexes — needs to be heavily regulated, as the sun's energy supply can vary over many orders of magnitude. Observing hundreds of individual light-harvesting complexes has now provided important insights into the machinery that regulates this process.

Natural products contain a range of chemical structures optimized for biological interactions. Fragmenting these compounds could help to combine this diversity with the broad coverage of chemical space offered by fragment-based drug discovery, and help to improve the efficiency with which screening hits can become successful drugs.

The design of a small-molecule library for drug discovery attempts to combine the favourable diversity of natural product structures with the modularity of peptide synthesis.

Nature assembles complex natural products using bifunctional building blocks and a mere handful of reaction types. Mimicry of this method seeks to revolutionize natural product and small-molecule synthesis.

Negatively charged lysine acylations—malonylation, succinylation and glutarylation—impact protein structure and function, which can affect cellular processes. Now temporarily masked thioester derivatives of succinylation and glutarylation can be used for site-specific modification of diverse bacterial and mammalian proteins, which can facilitate the study of how these lysine modifications impact enzymatic activity and control protein–protein and protein–DNA interactions.

Radical polymerizations yield polymers that cannot easily be degraded. The co-polymerization of cyclobutene-based monomers with conventional vinyl monomers has now been shown to result in co-polymers with cyclobutane mechanophores in their backbone, which facilitate on-demand degradation through a combination of mechanical activation and hydrolysis. This approach offers a promising avenue for the degradation of all-carbon-bond-backbone polymers.

X-ray diffraction analysis typically affords the static 3D structures of given compounds or materials, but to understand chemical processes, the visualization of fast structural changes is desirable. Time-resolved femtosecond crystallography has now been used to monitor the structural dynamics of a photoactive metal–organic framework.

The precision synthesis of cyclic polymers with ultrahigh molar mass (UHMM) and circularity is challenging. Now, a method that involves superbase-mediated living linear-chain growth followed by macromolecular cyclization triggered by protic quenching enables the on-demand production of UHMM cyclic polymers with a narrow dispersity and closed-loop chemical recyclability.

Photoinduced electron transfer (PET) occurs in many chemical processes and has various applications. Here ionizing radiation was used to trigger PET for controlled drug release from an antibody–drug conjugate using a picolinium cage. The radiotherapy-activated prodrug system demonstrated high antitumour efficacy and minimal side effects.

Carbon capture, utilization and storage is key for climate change mitigation and developing more environmentally friendly technologies. Now it has been shown that CO₂ capture in single-component water-lean solvents is accompanied by the self-assembly of reverse-micelle-like tetrameric clusters in solution that enable the formation of various CO₂-containing compounds.

RNA localization is key to regulating cellular function but is challenging to measure in an unbiased manner. Now a combination of enol-masked acylating probes with a bioorthogonal esterase to locally unmask them provides a non-radical RNA proximity labelling platform—termed BAP-seq—that enables the generation of high-resolution spatial maps of RNA.

The development of new methodologies to convert plastics into fuels without relying on noble metal-based catalysts is desirable. Now it is shown that a layered self-pillared zeolite enables the conversion of polyethylene to gasoline with a selectivity of 99% and yields of >80% without the need to use external hydrogen.

Despite the widespread utility of ruthenium catalysts, many protocols for their use require high temperatures or light irradiation. Now, the synthesis of an air- and moisture-stable ruthenium precatalyst has been reported. This versatile catalyst drives an array of transformations and enables rapid screening and optimization of reactions, revealing previously unknown in situ generated ruthenium complexes.

Lithium metal batteries are an attractive energy storage technology, but their development relies on the complex interplay between the components’ chemical, physical and mechanical properties. Now, selective methylation of dimethoxyethane ether electrolytes is shown to improve electrolyte, electrode and solid–electrolyte interphase stabilities to enable high-performance 4.3 V lithium metal batteries.

Accessing longer-wavelength emitting organic fluorophores is critical for diagnostic imaging. Here a series of silicon-RosIndolizine fluorophores with emission maxima at 1,300 nm, 1,550 nm and 1,700 nm were synthesized. The fluorophores generate high-resolution in vivo fluorescence images in mice and establish design principles for future shortwave-infrared fluorophore designs.

Ribosomally synthesized and post-translationally modified peptides (RiPPs) can have vast structural diversity and biological functions enabled by disparate post-translational modifications (PTMs). However, unconventional PTMs derived from non-RiPP biosynthesis are rarely reported. Now a class of lipopeptides featuring a distinct fatty-acyl-modified N terminus and the responsible RiPP/fatty-acid hybrid biosynthetic machinery have been characterized.

Excited by the prospect of future missions to the Jupiter system, Bruce Gibb explores the chemistry of Jupiter’s moons and wonders whether there could be life on Europa.

The redox properties of visible-light-absorbing photosensitizers are limited by the energy of visible photons, but methods using sensitization-initiated electron transfer have recently been developed to address these challenges. Now a multiphoton dual-catalyst strategy has been used to enable the enantioselective de Mayo reaction for the synthesis of enantioenriched 1,5-diketones.

Chlorine-containing waste streams pose potential risks to human health and the environment, so their remediation represents a significant challenge. Now, chlorinated wastes have been successfully repurposed as chlorinating reagents for use in the preparation of organic chemicals and pharmaceutical ingredients.

Understanding the ways by which metal-containing catalysts carry out a reaction is a chemical puzzle. Now, investigations of a multi-metallic molecular system uncover how the self-assembly of molecular catalysts facilitates cooperation between active species and improves the conversion of water to hydrogen gas.

Natural protein folding takes place in aqueous cell environments. Now, it has been found that proteins in a water-free environment undergo faster and more efficient folding.

Key molecular features that drive protein liquid–liquid phase separation (LLPS) for biomolecular condensate have been reported. A spectrum of additional interactions that influence protein LLPS and material properties have now been characterized. These interactions extend beyond a limited set of residue types and can be modulated by environmental factors such as temperature and salt concentration.

High-throughput proteome-wide methods for identifying endogenous proteins that phase separate or partition into condensates during certain physiological events are needed but remain a challenge. Now, a high-throughput, unbiased and quantitative strategy can identify endogenous biomolecular condensates and screen proteins involved in phase separation on a proteome-wide scale.

Although the light-driven generation of hydrogen from water is a promising approach to renewable fuels, the H–H bond formation step represents a persistent mechanistic question. Now light-harvesting molecular catalysts have been shown to self-assemble into nanoscale aggregates that feature improved efficiency for photoelectrochemical H₂ evolution.

Time-resolved femtosecond crystallography (TR-SFX) is a powerful technique to monitor structural transitions in protein crystals at the atomic level, but its use in non-protein synthetic materials remains limited. Now TR-SFX has been used to visualize the structural dynamics of metal–organic frameworks, showing the potential of this tool to study the dynamic motion of crystalline porous materials.