Articles in 2020

The reactivity of transient carbocations provides interesting synthetic opportunities, but the selectivity control is challenging. Now, catalytic access to carbocation intermediates via metal-nitrenoid transfer into alkenes is reported and their regiocontrolled elimination is achieved, allowing the production of allylic lactams.

The use of a bibliography in scientific literature has evolved over time. Here, we look at its history and the roles it plays in contemporary science.

The carboazidation of olefins represents an effective strategy to introduce both carbon and nitrogen substituents into hydrocarbons, but asymmetric versions of this reaction remain elusive. Now, an iron-catalysed asymmetric radical carboazidation is introduced that yields chiral halogenated organoazides in high enantiomeric ratios.

Tetraarylmethanes display special properties due to their spherical nature and are applied in various areas, but strategies for their asymmetric production are lacking. Now, their enantioselective synthesis is reported and in vitro studies indicate their potential as anticancer agents.

Obtaining spatially resolved spectroscopic information for catalysts under working conditions remains challenging. Here, an approach that combines X-ray absorption spectroscopy with microtomography is introduced and showcased for the selective catalytic reduction of NO_x with ammonia over a Cu-SSZ-13 washcoated monolith catalyst.

The rational design of efficient water oxidation electrocatalysts is paramount to the development of electrochemical devices. Now, a Co-TiO₂ single-site catalyst is presented for alkaline water oxidation with high intrinsic activity, and its mechanism has been studied by grand canonical quantum mechanics calculations and in situ techniques.

Fe–N–C materials are a promising alternative to platinum for catalysing the oxygen reduction reaction in acidic polymer fuel cells. Now, a ⁵⁷Fe Mössbauer study reveals that while these catalysts initially comprise two distinct FeN_x sites, a high-spin FeN₄C₁₂ and a low- or intermediate-spin FeN₄C₁₀, only the latter is durable in operating conditions.

Electrochemical conversion of CO₂ into value-added chemicals holds promise to enable the transition to carbon neutrality, but enhancing the selectivity toward a specific hydrocarbon product remains a challenging task. Now, the authors present a Cu–polyamine hybrid catalyst that achieves Faradaic efficiency of 87% for ethylene and full-cell energy efficiency of 50%.

Preparative methods for thioester and tertiary amide formation are currently missing in the biocatalysis repertoire. Now, a mutation of serine to cysteine in the catalytic triad of an acyltransferase expands its synthetic capability to generate these compounds while retaining its natural activity towards alcohols.

Platinum-group-metal-free, non-iron catalysts are highly desirable for the oxygen reduction reaction at proton exchange membrane (PEM) fuel cell cathodes, as they avoid the detrimental Fenton reactions. Now, a cobalt and nitrogen co-doped carbon catalyst with atomically dispersed porphyrin-like CoN₄C₁₂ sites is reported with an improved activity and durability in PEM fuel cell conditions.

Although the light-promoted Sabatier reaction has great potential for CO₂ remediation strategies, its mechanism is not fully understood. Now, a steady-state isotopic kinetic analysis coupled with infrared spectroscopy reveals important aspects of this hydrogenation process over a NiO_x/La₂O₃@TiO₂ composite catalyst.

Supramolecular hosts can readily self-assemble from simple components and allow remarkable chemical rate enhancements and product selectivity utilising defined microenvironments and specific host–guest interactions. This Review Article describes recent conceptual and catalytic advances made in this field.

Despite their promising optical properties, organolead halide perovskites are not frequently used in photocatalysis due to their low stability in water. Here, a long-lasting semiconductive organolead iodide layered crystalline material with the ability to perform overall water splitting is introduced.

Nickel–iron and cobalt–iron (oxy)hydroxides are state-of-the-art electrocatalysts for oxygen production in alkaline conditions. Now, the addition of high-valent dopants has been demonstrated to further propel the catalytic rate in these materials by an order of magnitude.

Controlling the regioselectivity in the coupling of simple aromatics is challenging. Now, para–para selectivity is achieved during the aerobic dehydrogenative homocoupling of arenes through a shape-selective catalyst based on molecular palladium confined within the framework of zeolite materials.

The Fischer–Tropsch product, water, is regularly hypothesized to be the driving force for catalyst deactivation. Cobalt nanoparticles may be oxidized to CoO, form mixed-metal oxides with supports, or sinter to larger particles. This Comment discusses the feasibility of these deactivation pathways, highlighting the importance of in situ characterization.

DNA-based dynamic networks show adaptation to external stimuli toward the generation of the fittest constituent. This selection principle has now been implemented to control the catalytic efficiency of an enzymatic reaction.