Articles in 2019

Enzymes require many, often hundreds, of amino acid residues arranged in a protein fold to promote catalysis. Now, self-assembly of a single amino acid — phenylalanine — in the presence of zinc is shown to form supramolecular structures that promote hydrolysis better than natural enzymes on a weight basis.

Bio-inspired by cellular respiration, the richness of oxygen redox chemistry is a cutting-edge field for building lithium batteries. While the Li–air battery uses external oxygen, a new lithium battery offers a high energy-density and long-term cycling stability just by confining oxygen and lithium between graphene oxides.

Plastic waste is a serious matter of concern due to its disruptive impact on the environment. While disposal and reclaim strategies represent the first lines of intervention to solve this problem, upcycling options based on catalytic transformations will eventually be necessary to reconvert enormous quantities of such material.

The synthesis of chiral amines is of crucial importance for the pharmaceutical industry, but it remains a challenging task and is often inefficient. Now, a heterogeneous iridium complex is developed for the asymmetric hydrogenation of imines and the asymmetric reductive amination of carbonyl compounds in continuous flow with high yields and enantioselectivities.

The electrocatalytic upgrading of CO to higher-value feedstocks provides a promising route to multicarbon products. Here, the authors show that high ethylene selectivity can be achieved by constraining CO availability on copper, with an ethylene Faradaic efficiency of 72% and a partial current density of >800 mA cm⁻².

The asymmetric hydrogenation of alkenes is a common route to optically active compounds, but alkene synthesis is often atom-inefficient, and the formation of isomers further complicates the procedure. Now the Ir-catalysed deoxygenation of racemic alcohols is shown to be a simple route to enantioenriched products.

Photocatalytic activation of alkyl carbon–chlorine bonds has constantly proven difficult due to the high energies needed to cleave this stable bond. Here a surfactant-based photocatalytic system is used, allowing for the radical dehalogenation and subsequent reactivity of unactivated alkyl chlorides.

Methods to control the performance of heterogeneous catalysts are extremely relevant to the success of industrial processes. This review provides a rationalization of the effects that metal support interactions have on the reactivity of different catalytic systems, emphasizing strategies to tune such effects.

The energies of the species in a given reaction network are linked by linear scaling relationships, limiting the design of catalysts with improved activity and selectivity. In this Perspective, López and Pérez-Ramírez discuss strategies to circumvent such scaling relationships.

Deuterated molecules are important both as labelled probes and as targets in their own right. Here the authors report a very simple and general deuteration of aldehydes, by the use of an N-heterocyclic carbene catalyst in the presence of D₂O.

Due to its stability nitrogen is often employed as an inert gas during catalytic reactions. Now, a study shows that N₂ can act as promoter for the catalytic hydrodeoxygenation of p-cresol on supported ruthenium catalysts through the formation of hydrogenated nitrogen species acting as a source of protic hydrogen.

This work shows that the biosynthesis of the polyether tetronasin involves an apparent enzyme-catalysed inverse-electron-demand hetero-Diels–Alder reaction to form an unexpected oxadecalin intermediate. A second enzyme then rearranges the oxadecalin to form the four-ringed tetronasin.

To achieve large-scale application of water electrolysers we need to find optimal cathode and anode catalysts. This work reports an engineered silver catalyst with high density of stacking faults that exhibits high activity and stability for the hydrogen evolution reaction, outperforming commercial platinum on carbon.

Imine reductases are promising catalysts, facilitating a direct stereoselective route to secondary amines. Now, protein engineering has created stable and efficient variants that allow their application in kilogram-scale synthesis.

Given the importance of enantioenriched β²- and β³-amino acids as building blocks, direct and versatile methods for their synthesis are highly coveted by organic chemists. Now, using easily accessible 1,3-oxazinane motifs, a regiodivergent and enantioselective C–H functionalization method permits their synthesis in a straightforward and practical fashion.

The design of heterogeneous catalysts with tunable activity and selectivity constitutes a remarkable challenge. Now, a synthetic approach towards producing nanocrystals encapsulated within polymer layers has been developed, unravelling the principles to achieve control of transition state and product diffusion using CO oxidation as a case study.