Reviews & Analysis

Non-canonical amino acids are important building blocks for natural products but finding them is nontrivial. Now, transfer RNA deacylases have proved their utility as markers for biosynthetic gene clusters producing non-canonical amino acids, thereby accelerating the discovery of atypical natural products.

The oxygen evolution reaction remains a bottleneck for renewable fuels research. Now, temperature-dependent electrochemistry and operando X-ray characterization demonstrate that both catalyst restructuring and solvent ordering dictate reaction kinetics, offering new insights for engineering electrode–electrolyte interfaces.

To control the magnetic anisotropy of single-molecule magnets, precise engineering of the ligands is crucial. Now, homoleptic bis(stannolediide) complexes are synthesized with trivalent terbium, as well as trivalent and divalent dysprosium, expanding the series of axially coordinated lanthanide single-molecule magnets.

Single-crystalline two-dimensional poly(arylene vinylene) frameworks are emerging as promising materials for electronic and photocatalytic applications. Now, a Mannich-elimination strategy enables their synthesis via topological conversion of imine covalent organic frameworks. Preserving lattice order during the linkage transformation is key for achieving enhanced conjugation and robust electronic performance.

Vinylcyclopropane-cyclopentene rearrangements provide access to five-membered carbocycles, yet enantioselective variants have largely been confined to electronically activated substrates. Now, a rhodium-catalysed enantioselective rearrangement of gem-difluorocyclopropanes proceeds with a striking chemodivergence, depending on whether the reaction is performed in glass or plastic.

Semicrystalline polymers are formed when polymer chains have sufficient stereo- and regioregularity, but some unusual atactic polymers can also crystallize despite their lack of regularity, resulting in semicrystalline materials. This Review highlights the factors that induce crystallization in atactic polymers and describes tools for synthesizing them.

The oxidative ring opening and functionalization of strained rings is a reactive paradigm capable of highly practical and far-reaching applications. Now, an oxidative platform for the activation of simple cyclopropanes and cyclobutanes has been developed as a highly enabling technology.

Radical molecules and extended nitrogen chains are notoriously difficult to stabilize. Now, a series of molecules featuring four-atom nitrogen chain radical anions that are not supported by metals have been synthesized.

Solid-phase peptide synthesis enables the study of countless peptides, but aggregation during synthesis hinders production of many sequences of interest. Now, machine learning models enable prior identification of aggregation-prone sequences, and highlight amino acid composition, rather than specific sequence, as the major determinant of aggregation.

Electrocatalysts facilitate the multi-step proton–electron transfer reactions at the heart of renewable energy chemistry, but their mechanisms can be difficult to understand and control. Now, new research shows how hydrogen isotope-exchange experiments clarify the rate-limiting step and how structural disorder can alter it.

Researchers typically view electrocatalysis as an interfacial phenomenon, unfolding at the junction of solid electrodes, liquid electrolytes, and reacting molecules. Now, a new study finds bulk water itself can act as an active redox participant, forming radicals in solution that activate reactants before they reach the electrode.

We developed a strategy to repurpose rare codons in mammalian cells, enabling the simultaneous incorporation of up to five distinct noncanonical amino acids into a single protein. By avoiding previous limitations in genetic code expansion using stop codons, this rare codon recoding facilitated advanced protein engineering applications.

Although synthetic gene networks with various DNA architectures can process molecular information in cells, their large size and genetic role limit the systems that can be designed. Here, we engineer retron DNAs to recruit DNA-binding proteins and demonstrate their use as non-genetic molecular baits in several synthetic biology applications.

The synthesis of organoarsenicals has traditionally involved multistep procedures and the use of toxic arsenical reagents, impeding their widespread application. Now, a photocatalytic approach enables the direct conversion of arsenic sulfide minerals, such as orpiment, into various organoarsenicals using visible light.

Electricity-driven carbon dioxide reduction offers a renewable method to upcycle CO₂; however, understanding the role of the electrolyte remains a challenge. Now, carbonate anions have been found to influence reactivity via radical-mediated mechanisms to enhance proton delivery and act as a carbon source.

Carbocyclic[n.1.1]propellanes have captivated synthetic and physical organic chemists for decades owing to their strained structures and interesting bonding. Now, a unified synthesis of heteroatom-containing [3.1.1]propellanes has been realized as an entry point to diverse multicyclic ring architectures.

The enzymatic synthesis of azetidines is a prime example of the superiority natural systems often show over laboratory syntheses, but how nature achieves such difficult transformations in mild conditions is unclear. Now, two independent reports have revealed that the azetidine ring of polyoxamic acid arises from L-isoleucine via a dual-enzyme system that overcomes major energetic barriers through coordinated metalloenzyme chemistry.

Transition-metal chemistry has transformed modern organic synthesis, enabling the generation of novel compounds in vitro. Now, biocompatible organometallic reagents have been shown to enable selective transformations in complex biological settings, allowing precise protein modification and profiling in living cells.

Emulating biological transcription using artificial synthetic circuits is a key challenge in advancing systems chemistry. This Review discusses synthetic transcription circuits that are dynamically triggered to drive switchable, dissipative, oscillatory and bistable reaction models, mimicking native processes. These circuits are proposed as critical machineries for sensing and theragnostics.

The [2+2] cycloaddition of two alkenes is the most efficient route to four-membered carbocycles, but it is thermally forbidden. Now, installing fluorine atoms at the alkene terminus enables intramolecular thermally crossed [2+2] cycloaddition, providing a strategy for constructing gem-difluoro heterobicyclo[n.1.1]alkanes.