Reviews & Analysis

An organic quantum magnet has been prepared in short chains of porphyrin derivatives through a combination of on-surface synthesis and atom manipulation using the tip of a scanning probe microscope.

Radical-mediated functionalization streamlines access to complex synthetic targets. Now, a sulfonium-based donor–acceptor pair enables photoinduced charge-transfer interactions to access electronically diverse aryl radicals. Reaction with enol ethers or isocyanide provides a metal-free method for arene functionalization.

The light-driven conversion of abundant resources such as CO₂ and H₂O into chemical fuels for energy storage is crucial to end our dependence on fossil fuels. This Review highlights how molecular catalysts and photosensitizers can be grafted onto metal–organic frameworks to combine the advantages of both classes of compounds. Different synthetic strategies are discussed, along with their advantages and limitations.

The direct carbon isotope exchange reaction on α-amino acids is highly desirable, as existing labelling methods require several synthetic steps and harsh conditions. Now, an aldehyde-catalysed carboxylate exchange with isotopically labelled *CO₂ has enabled the direct formation of ¹¹C, ¹³C and ¹⁴C-labelled α-amino acids.

The study of rare isotopes, including many in the f-block, is a key step to advancing our fundamental understanding of these elements, but their scarcity poses challenges. Now, minute amounts of such materials have been isolated and characterized through complexation with polyoxometalate clusters.

Hydrogen, which possesses the highest gravimetric energy density of any energy carrier, is attractive for both mobile and stationary power, but its low volumetric energy density poses major storage and transport challenges. This Perspective delineates potential use cases and defines the challenges facing the development of materials for efficient hydrogen storage.

DNA nanotechnology and synthetic biology both aim to expand the range of dynamic behaviours exhibited by rationally programmed biomolecules. Now, the programmability of synthetic transcriptional circuits has been improved to enable synthesis of dynamic biomolecular circuits with unmatched complexity.

Noyori-type catalysts and inorganic bases are frequently used together for homogeneous hydrogenation, but key intermediates have not yet been isolated. Now, the structure and reactivity of a long-postulated intermediate — the alkali metal amidate complex — have been reported through experimental and computational studies.

Aqueous organic redox flow batteries are promising for low-cost and large-scale energy storage, but the redox-active molecules they rely on degrade prematurely. Now, a facile electrochemical protocol to regenerate them has been proposed, resulting in extended battery lifetimes.

Quantitatively studying the partitioning of biomolecules and reaction equilibria in cellular systems is an enormous challenge. Now, a multiphase coacervate model system provides insight into this complex biological problem, illustrating how coexisting phases influence RNA partitioning and duplex dissociation.

Amines with free N–H groups have long posed a tremendous challenge in transition metal-catalysed amination reactions. Now, use of a bidentate phosphorus ligand enables the palladium-catalysed oxidative amination of simple olefins with Lewis basic amines, with no prefunctionalization, forming both alkyl and aryl allylamines.

The application of machine learning to big data, to make quantitative predictions about reaction outcomes, has been fraught with failure. This is because so many chemical-reaction data are not fit for purpose, but predictions would be less error-prone if synthetic chemists changed their reaction design and reporting practices.

A grand challenge for bio-based plastics is the ability to cost-effectively manufacture high-performance polymers directly from renewable resources that are also recyclable-by-design. A one-step conversion of xylose to polyesters has been reported, combining a sustainable lifecycle with impressive materials performance.

An alcohol-functionalized cyclophane has been shown to form a bowl-shaped cavity large enough to host tris(bipyridine)ruthenium(ii). The macrocycle captures, and suppresses the activity of, the ruthenium complex in water but, when oxidized to its ketone-bearing counterpart, releases the ruthenium guest.

Supramolecular catalysis can emulate many features of enzymatic transformations. Now, a complex proton wire mechanism — enabling the dual activation of a nucleophile and an electrophile through reciprocal proton transfer — has been shown to operate during the β-glycosylation of sugars within a self-assembled capsule.

Malleicyprols are highly reactive polyketides responsible for virulence in some pathogenic bacteria. Now, the enzyme that constructs the cyclopropanol warhead of malleicyprols has been identified. This enzyme could represent a useful target for developing new antivirulence therapeutics.

How electric fields generated by enzyme active sites push and pull on substrates is important to their chemistry, but measuring them is difficult. Now, the electric field within an active site has been measured along two directions using a vibrational probe, revealing that the field effect in enzymes is different compared with that in bulk solvents.

The rational synthesis of advanced porous materials that mimic the behaviours of biological proteins remains challenging. Now, a distinct type of crystalline porous peptide framework has been prepared through bioinspired noncovalent assembly, enabling chemical tuning of the properties and functions of the pore environments.

N-heterocycles are valuable motifs in pharmaceuticals and materials, but divergent synthetic strategies are lacking. Now, bifunctional sulfilimines have been shown to form nitrogen-centred radicals under photocatalytic conditions, and subsequent coupling with olefins enables the synthesis of diverse N-heterocycles.