Volume 3 Issue 4, April 2020

Understanding the surface structure of a catalyst under a reaction environment is challenging, yet necessary. Now, a combination of in situ methods reveals the reversible formation of a surface alloy as the active phase for core–shell Ni–Au nanoparticles during CO₂ hydrogenation, which could not be detected by ex situ methods.

The chemoenzymatic potential for the construction of complex chiral molecules has not been fully explored. Now, Candida antarctica lipase B has been used to synthesize complex functionalized planar chiral macrocycles, providing a platform for the efficient and sustainable preparation of molecules that are of particular interest in drug discovery.

Radical S-adenosyl-l-methionine enzymes catalyse challenging chemical reactions, showing potential for biotechnological applications. This Review focuses on enzyme structure–function relationships, providing insights on how these biocatalysts perform different reactions and control the reactive radical species.

Bicyclo[1.1.1]pentanes are of interest to the pharmaceutical and chemical communities, due largely to their metabolic stability and potential as bioisosteres. Here the enantioselective C–H activation of these carbocycles is reported, giving access to enantioenriched, substituted products while maintaining the carbocyclic framework.

The cross-coupling of C–H bonds with alcohols is a highly efficient route to ethers. Here the authors report such an oxidative coupling, by use of a radical relay to both promote hydrogen atom transfer and activate the copper catalyst for cross-coupling.

Supported single atoms can minimize metal utilization in catalysis, although reactivity restrictions exist. Here, fully exposed Pt, Pd and Rh ensembles localized on CeO₂ islands anchored onto partially reduced γ-Al₂O₃ are introduced as a superior and durable alternative for three-way catalysis.

Platinum nanoparticles have been neglected as a catalyst for acetylene hydrochlorination due to their limited activity. Here, the authors show that nanostructuring to the single-atom level renders platinum on carbonaceous supports a superior catalyst for this important industrial process.

There are very few methods for the organocatalytic aziridination of unactivated olefins. Here the authors report a simple ketone catalyst for the transfer of nitrogen to isolated carbon–carbon double bonds, with good substrate scope and in high yields.

Palladium-catalysed allylic substitution is a widely used method in organic synthesis, although it requires prefunctionalized starting materials or stoichiometric oxidants. Here the authors report a radical route to form π-allylpalladium complexes, and develop a 1,4-aminoalkylation of dienes under redox-neutral conditions.

The high reactivity of open-shell alkyl radicals makes their use in asymmetric catalysis challenging. Here the authors report a catalytic enantioselective desymmetrizing reaction of alkyl radicals and diols, forming stereocentres at the reaction site and at sites remote from it.

The structure of core–shell catalysts is often assumed to be conserved over a reaction. Now, an in situ study reveals that the shell of Ni@Au nanoparticles is reversibly converted into a Ni–Au alloy during CO₂ hydrogenation, with important mechanistic implications.