Articles

A common problem with double C–H activation/cross-coupling is the formation of homocoupled products. Here, the authors show that an ionic group on one reagent during Fe catalysed cross-couplings can lead to a clearly defined order of C–H activation and hence the avoidance of homocoupled side-products.

Axially chiral biaryls have proven to have a wide variety of uses—perhaps most importantly as ligands in asymmetric catalysis—but their synthesis remains challenging. Here, Bin Tan and colleagues report a redox-neutral aryl–aryl coupling, providing a direct route to N,N and N,O axially chiral biaryls in high yields and enantioselectivities.

While organolithium and organomagnesium compounds have well developed methods in organic chemistry, organosodium compounds are much less widely used. Here a method to generate organosodium compounds from aryl chlorides and (hetero)arenes is reported, along with a demonstration of their use in cross-coupling reactions.

New enzymes for the efficient and stereoselective synthesis of chiral amines are of high interest for the pharmaceutical industry. Now, Grogan, Vergne-Vaxelaire and co-workers report the discovery, characterization, crystal structure and engineering of a family of native amine dehydrogenases for the preparation of chiral amines from ketones.

While Ru-based electrocatalysts are among the most active for acidic water oxidation, they suffer from severe deactivation. Now, Yuen Wu, Wei-Xue Li and co-workers report a core–shell Ru₁–Pt₃Cu catalyst with surface-dispersed Ru atoms for a highly active and stable oxygen evolution reaction in acid electrolyte.

The electrocatalytic reduction of carbonyl groups is gaining attention in the context of biorefinery. However, fundamental knowledge on such processes is still limited. Now, the selectivity for the electroreduction of acetone on platinum single crystals is studied, revealing a remarkable structural sensitivity.

The electrochemical reduction of nitrogen to ammonia represents a challenge of major interest that would substantially decrease the burden of the energy-consuming Haber–Bosch process. Now, Yin, Yan, Zhang, Si and colleagues achieve high ammonia yield and Faradaic efficiency over 66% using bismuth nanocatalysts promoted by alkali cations.

Iron single-atom catalysts are among the most promising fuel cell cathode materials in acid electrolyte solution. Now, Shui, Xu and co-workers report concave-shaped Fe–N–C nanoparticles with increased availability of active sites and improved mass transport, meeting the US Department of Energy 2018 target for platinum-group metal-free fuel cell catalysts.

Metal oxides have been identified as a promising class of catalysts for carbon–oxygen bond cleavage in the context of biomass valorization, although the systematic understanding of their reactivity remains elusive. Now, a combination of catalytic screening and first principles calculations provide important insights into this family of catalysts.

Photoelectrochemical cells have been widely used for the production of solar fuels, but have seen limited applications in organic synthesis. Here the authors demonstrate photoelectrocatalytic C–H amination of aromatics, using haematite as the photoanode.

Copper on ceria is an excellent catalyst for the low-temperature water–gas shift reaction. Here the active sites are directly imaged by electron microscopy and probed with in situ spectroscopy, showing that the reaction proceeds via a cooperative mechanism whereby the Cu⁺ chemically adsorbs CO while an adjacent O_v–Ce³⁺ site dissociatively activates H₂O.

Chiral γ-lactams are of significant interest being present in numerous pharmaceutical agents; however, their chemical synthesis is complex, requiring pre-functionalized starting materials. Now, Park and Chang report an iridium-based catalyst system for the production of chiral γ-lactams from an abundant feedstock via an intramolecular asymmetric sp³ C−H amidation.

Low-molecular-weight, highly branched polyethylenes are attractive candidates for synthetic lubricants, but their efficient production is constrained by a lack of effective catalytic methods. While conventional group IV transition metal catalysts produce diverse polyethylenes on a huge scale, they are unable to produce highly branched polyethylenes. Here a hydrocarbon-soluble organozirconium precatalyst and borate cocatalyst produce the desired polyethylenes with excellent activity and branch selectivity.

Cell viability depends on transcriptional fidelity, but the proofreading mechanism of eukaryotic RNA polymerase II (Pol II) remained elusive. Now, Cheung, Wang, Zhang, Huang and co-workers show that Pol II utilizes the downstream phosphate oxygen of the RNA transcript to activate intrinsic cleavage of misincorporated nucleotides.

The upgrade of carbon monoxide to higher alcohols offers a route to renewable fuels. Now, Sinton, Sargent and co-workers report a highly fragmented, copper-based catalyst with engineered interfaces between the (111) and (100) facets that promote the coupling of C₁ and C₂ species, leading to enhanced production of n-propanol.

Samarium iodide is a remarkably useful and mild reductant in organic synthesis, but its use can be problematic due to the need for (super)stoichiometric loadings. Now a method that employs samarium iodide as a catalyst—without the need for a stoichiometric co-reductant—is reported. Loadings as low as 5% are shown to catalyse radical cyclization cascades.

Hydrogen atom transfer processes are commonly encountered in chemical and biological systems. Here the authors report a redox-neutral hydrogen atom transfer through the activation of hydrosilanes with a Lewis base. Further, they demonstrate that this initial step can be directed towards hydrosilylation or polymerization depending on the choice of catalyst.

The selective catalytic oxidation of ammonia with palladium is an important reaction in the context of NO_x abatement, although limited structural information about the catalyst under reaction conditions is available. Now, an operando study reveals the speciation of palladium and identifies crucial palladium–nitride species.

MOFs have found limited application in catalysis so far, as the result of their limited thermal and hydrolytic stability. Now, non-thermal plasma is shown to be able to promote and sustain the activity of HKUST-1 and other MOFs towards the water–gas shift reaction despite the presence of water. [In a previous version of the graphical abstract, CO conversion was incorrectly labelled CO₂ conversion.]

The ability to functionalize normally unreactive sites in molecules opens up tremendous flexibility in synthesis design and structural modification, in addition to reducing the need for multiple steps or highly reactive reagents. Now, a dual-catalytic strategy, demonstrated with the methods for the β-arylation of aliphatic alcohols and for the enantioselective γ-hydroarylation of allylic alcohols, is reported for such reactions.