Articles in 2022

Biocatalytic methods to access thioesters, such as acyl-coenzyme A, from carboxylic acids are underdeveloped. Now, it is shown that the adenylation domain of a carboxylic acid reductase enzyme can be exploited as a promiscuous thioester synthetase and combination with acyltransferases facilitates the synthesis of amides and peptide labelling.

Hydrogenolysis of unactivated C(aryl)–C(alkyl) bonds is a challenging task even in the presence of metal catalysts. Now, an approach using a boron catalyst is described that facilitates the hydrogenolysis of alkylarenes under mild conditions, and its utility is demonstrated by degrading polystyrene waste into benzene and phenylalkanes.

Controlling the stereochemical outcomes of chemical reactions is essential in modern chemical synthesis and manufacturing. Now, a nickel-catalysed, stereoselective hydrometalation and enantioconvergent alkyl–alkyl coupling of alkenyl boronic esters and α-bromo carbonyl derivatives has been achieved to provide single stereoisomers.

Simultaneous stereochemical control of two vicinal C(sp³) stereocentres from two reaction partners is challenging. Now, this is achieved in a nickel-catalysed enantio- and diastereoselective cross-coupling reaction of internal alkenes with racemic alkyl bromides.

Electrocatalytic hydrogenations of organics allow water to be used as the proton source but are limited by low substrate solubility in aqueous media or by low performance in organic electrolytes. Now, a Pickering emulsion system for electrocatalytic hydrogenation is presented to overcome those issues, where the hydrogenation reaction occurs at the interface between the aqueous and organic phases.

High current densities during CO₂ reduction in gas diffusion electrode (GDE) flow cells are incompatible with present online product-profiling methods. With the adaptation of proton-transfer reaction time-of-flight mass spectrometry, operando mechanistic information on C₁–C₄ product formation at copper-based GDEs is now accessible.

The 27th United Nations Climate Change Conference placed the risks of greenwashing under the spotlight. In this Editorial, we reflect on the implications of this phenomenon for science and peer review.

Operando investigation of the CO₂ reduction mechanism at gas diffusion electrodes is a challenging task. Here proton-transfer-reaction time-of-flight mass spectrometry has been deployed to analyse the intermediates and products at copper electrodes in real time.

Activation of inert chemical bonds employing classical photocatalysts usually involves an outer-sphere single electron transfer mechanism. Now, an alternative inner-sphere single electron transfer pathway for the homolytic cleavage of strong C–Cl bonds using gold catalysts is reported.

The Birch reduction is one of the methods of choice to perform the hydrogenation of arenes, although it requires the handling of pyrophoric substances and ammonia at cryogenic temperatures. Here a photocatalytic approach based on boron carbonitride introduces the possibility to hydrogenate (hetero)arenes under mild conditions in water.

Despite great progress in electrocatalytic CO₂ reduction on Cu-based materials, the selectivity for methanol has remained elusive in contrast to thermocatalytic routes. Here, using Cu₂NCN with polarized Cu atoms as the cathode, selectivity of up to 70% for methanol is achieved by favouring cleavage of Cu–O over O–C in the crucial Cu–*O–CH₃ intermediate.

While the promise of low metal utilization has brought single-atom catalysts (SACs) into the spotlight, intrinsic limits in reactivity still restrict their application to a small set of reactions. Here, the authors expand the repertoire of SAC transformations with a nitrogen-doped, carbon-supported, Ru single-atom catalyst that exploits the effect of peripheral N species to promote propane dehydrogenation.

Controlling selectivity during direct unsymmetrical diamination of double bonds is challenging. Now, ambiphilic iminyl and electrophilic amidyl radicals are generated from oxime ester-based bifunctional precursors, enabling the regio- and diastereoselective unsymmetrical diamination of arenes and alkenes.

Iridium catalysis can be used to achieve the challenging Z-retentive asymmetric allylic substitution reaction by trapping thermodynamically less stable anti-π-allyliridium intermediates. Now the isolation and characterization of these complexes is reported, providing hitherto elusive detailed mechanistic insights into this reaction.

The mode of action of the biological Dnd antiphage defence system to cleave foreign DNA was not known. Now the activities of Dnd protein complexes are revealed, and a mechanism to discriminate between self-DNA and invading DNA is proposed.