News & Views

The direct formation of C–N bonds onto arenes provides a simple route to synthesize a variety of important products. Now, formation of a highly polarized, aminium radical cation enables direct C–H amination, allowing the coupling of an exceptionally broad range of alkyl amines and arenes.

Natural products often provide lead scaffolds for the development of therapeutics, but complexity of their synthesis can limit the discovery of improved analogues. Pharmacophore-directed retrosynthesis aims to accelerate the building of a structure–activity relationship profile of a natural product, aiming to identifying a simplified lead.

The structure of self-assembled aggregates depends critically on the manner in which the building blocks organize themselves. Now, such a self-assembly process has been monitored in situ using liquid-phase transmission electron microscopy, unveiling a new pathway of vesicle formation.

Maleimide–thiol adducts are popular in both bioconjugation and materials chemistry, however, they are unstable under physiological conditions. Now, a mechanochemical approach uses pulling forces to stabilize maleimide–thiol adducts and improve the stability of polymer–protein conjugates.

Enzymatic approaches to synthesize oligosaccharides offer an alternative to chemical syntheses for the production of homogeneous glycans; however, enzyme-based routes typically require lengthy processes. Now, the design of a water-soluble affinity tag has enabled the automation of multistep enzymatic syntheses of mammalian oligosaccharides.

Gold — long presumed to be an inert metal — has been increasingly shaking this image over the past couple of decades, mostly through electrophilic behaviour. Now, a two-coordinate gold complex has been shown to exhibit nucleophilic reactivity, with the insertion of CO₂ into its polarized Au^δ−–Al^δ+ bond.

Finely tuned interactions in the second coordination sphere of enzymes or homogeneous catalysts can be essential for their function. Now, this concept has been applied to the surface of a catalytic material, utilizing pairs of Cu atoms for the selective electrochemical fixation of CO₂.

Most compounds form crystals so small that scientists cannot experimentally determine their atomic structures using X-ray crystallography. Microcrystal electron diffraction now provides a unique solution for this challenge.

Intersystem crossing plays a role in the mechanism of many reactive collisions between atomic species and organic molecules, and has been generally observed when the reactants are still approaching one another. Now, intersystem crossing has been observed to also occur after their initial interaction.

Strained boronate complexes have now been shown to enable an unprecedented cross-coupling reaction across a C–C σ-bond. Using this approach, highly functionalized cyclobutanes can be prepared with excellent stereocontrol from readily available reagents.

One goal of synthetic biologists is to develop artificial systems to help study biological processes. Now, cell communication and differentiation have been demonstrated using spatiotemporal patterns created in artificial multicellular compartments.

Gold nanomaterials are attractive for a variety of applications, including in medicine, but need to be made stable enough to operate in biological systems. Now, gold nanorods have been stabilized for photothermal therapy by sequential surface anchoring, using a bidendate PEG-based ligand that features a thiolate moiety and an Au–NHC moiety.

Covalent organic frameworks (COFs), whose heterogeneous backbones can be easily tuned at the molecular level, are promising photocatalysts for artificial photosynthesis. Sulfone-rich crystalline, wettable COFs have now been shown to exhibit high photocatalytic hydrogen evolution rates with platinum nanoparticles as co-catalysts.

Superoxide dismutase mimics can help regulate the levels of O₂^•− in the body, but typically rely on redox-active metals that are toxic in their free form. Now, a complex featuring a redox-active quinol moiety complexed to a redox-inactive zinc centre has been shown to catalyse O₂^•− dismutation.

Magnetic or electric fields have long been used to align or orient atomic or molecular species in a molecular beam. Now, experiments in a merged beam apparatus show that an external magnetic field can be used to favour one particular reaction path.

The structural features and catalytic performances of catalyst particles have now been correlated using a fluorescence microscopy approach, by tracking nanoprobes as well as fluorescent reaction products. Such mapping enables exploration of structure–function relationships, which is essential for the design of better catalysts.

The applicability of metal-organic frameworks (MOFs) — in spite of their obvious potential — is hindered by stability issues, in particular towards water. Now, a ‘crumple zone’ concept has been proposed in which the presence of sacrificial bonds protects a MOF without significantly altering its structure or functionality.

Dynamic covalent chemistry combines the error-correcting behaviour of supramolecular chemistry with the robustness of covalent bonding, but relies on a somewhat limited set of reactions. Now, the classic nucleophilic aromatic substitution (S_NAr) reaction has been shown to be reversible and self-correcting.

Probing single-atom alloys has shown that, when interactions between the components are weak, the electronic structure of the dilute element resembles that of a free atom, making bonding with reactants more like that in molecular homogeneous catalysts.