Reviews & Analysis

Fluoroalkyl fragments are ubiquitous motifs in pharmaceuticals and agrochemicals, but their introduction to a given molecule typically involves expensive or difficult-to-handle reagents. Now, the photocatalysed hydrofluoroalkylation of alkenes has been achieved using simple and readily available fluoroalkyl carboxylic acids.

Stereoselective decarboxylative protonation can produce diverse chiral molecules from widely available carboxylic acids. However, general and practical strategies are lacking. Now, a chiral spirocyclic phosphoric acid-catalysed decarboxylation of aminomalonic acids has enabled the modular synthesis of α-amino acids.

Recent improvements in de novo protein design are likely to support a broad range of applications, but larger complexes will be easier to create if a building block approach is adopted. Now protein filaments with tunable geometry can be made using assemblies that have both cyclic and superhelical symmetries aligned along the same axis.

Ribonucleoprotein granules are ubiquitous in living organisms with the protein and RNA components having distinct roles. In the absence of proteins, RNAs are shown to undergo phase separation upon heating. This transition is driven by desolvation entropy and ion-mediated crosslinking and is tuned by the chemical specificity of the RNA nucleobases.

To develop covalent inhibitors with high potency and low off-target effects, combinatorial approaches that search for candidates from large libraries are desired. Here, sulfur(VI) fluoride exchange (SuFEx) in vitro selection is established for the evolution of covalent aptamers from trillions of SuFEx-modified oligonucleotides. Through this technique, covalent aptamers with optimally balanced selectivity and reactivity are identified.

Open-shell organic molecules with properties that can be modulated by external stimuli are of interest for spintronics applications. Now, an overcrowded alkene with open-shell tetraradical character has been synthesized in which the interaction between the π-conjugated subunits depends on the charge and spin state.

Site-specific modification of RNA in cells is crucial for analysis and functional investigations. Natural enzymes that promote RNA methylation using S-adenosyl-l-methionine (SAM) exist, but leveraging these proteins for RNA modification is limited by cell permeability, stability and specificity of their substrates. Now, a de novo ribozyme that acts on a stabilized and cell-permeable SAM analogue enables site-specific RNA modification with a click handle in living cells.

Fluorination strategies are important in assisting the synthesis of pharmaceuticals. Iodine(I/III) catalysis has become particularly useful for installing gem-difluoro groups but is limited to styrenes. Now, the hypervalent iodane-catalysed difluorination of enynes has enabled access to diverse homopropargylic difluorides.

Organic chemists meet biennially to present exciting developments in the realm of synthesis. Thomas Barber discusses the standout themes of this year’s international synthesis in organic chemistry symposium.

Gas bubble accumulation at interfaces is a barrier to achieving more efficient electrochemical devices. A clever model system to understand bubble formation during electrochemical hydrogen evolution now reveals similarities between the forces at play during their detachment from the catalyst surface and those involved in wine climbing up a glass.

Aromatic oligoamide macrocycles have been developed in which the constrained backbone enforces hydrogen-bond donors to orient towards the macrocycle centre, forming a highly electropositive cavity. These macrocycles show strong binding for various anions and can partition into biomembranes to facilitate selective transmembrane anion transport.

The factors that control the solubility of a salt are many and varied. Now a set of salts with closely related cations suggests that weak London dispersion-controlled CH···π interactions can dominate solubility, despite the presence of much stronger forces.

The intentional interweaving of two different metal–organic framework (MOF) lattices could offer a strategy for combining the disparate properties of the two frameworks within a single MOF material. Now, the rational construction of such hetero-interpenetrated MOFs has been demonstrated.

Light is a major driver of the chemistry of the atmosphere and usually involves the photolytic fragmentation of molecules into radicals before their reaction. New results show that formaldehyde, excited by low-energy light, can react with oxygen, opening up alternative atmospheric oxidation pathways.

An infrared laser-induced temperature jump provides a rapid and broadly applicable perturbation to protein dynamics. Temperature-jump crystallography was paired with time-resolved X-ray crystallography to study the dynamic enzyme lysozyme. Measurements with and without a functional inhibitor revealed different patterns in the propagation of motion throughout the enzyme.

Experimental and computational studies establish the operation of Fe(iii)-based metalloradical catalysis for the asymmetric cyclopropanation of alkenes with different classes of diazo compounds. The reaction proceeds through a stepwise radical mechanism involving α-Fe(iv)-alkyl and γ-Fe(iv)-alkyl radical intermediates. This work provides a future direction for the development of metalloradical catalysis.

Deuterated compounds are used in many applications such as mass-spectrometry standards, drugs or in organic light-emitting diodes. Now, hydrogen-activated homogeneous pincer complex catalysts can be used to perform selective alkene deuteration with the cheapest available deuterium source, D₂O.