Volume 2 Issue 6, June 2019

Radical intermediates are key species in many chemical transformations. Recent advances have provided a new suite of selective radical alkylation reactions. This Comment highlights pioneering studies using alkyl amines that act as radical precursors in a number of catalytic processes by their conversion to alkylpyridinium salts.

Tailoring platinum-based catalysts is of great research interest in the fields of electrochemical energy conversion and storage, as well as other applications. Now, an approach has been developed to boost the activity of platinum catalysts at the atomic scale.

The biological functions of glycan motifs such as the Lewis blood antigens are often defined by their precise multivalent presentation on complex glycoconjugates, making synthesis particularly challenging. Access to a number of positionally defined Lewis motifs on natural polysaccharide scaffolds has now been achieved using bacterial glycosyltransferases.

Hydrogenases are very powerful biocatalysts for dihydrogen cleavage. Now, X-ray crystallography shows how [Fe]-hydrogenase requires ligand exchanges at the metal centre and significant molecular motions to open and close its active site to effectively transfer a hydride to an electrophilic organic substrate.

A synthetic DNA enzyme catalyses the formation of a native phosphodiester bond between two RNA fragments, but the molecular details of the mechanism remained elusive. Research using computational and biochemical approaches now suggests that the DNA enzyme recruits two magnesium ions to assist in the catalysis of RNA ligation.

While converting methane to methanol is an attractive process, making a catalytic—and commercially viable—route has presented severe difficulties. Here van Bokhoven and co-workers discuss the successes, problems and misconceptions in the field, focusing on the reaction with molecular oxygen over zeolites.

Platinum plays a crucial role in various electrocatalytic systems, but its scarcity and cost limit its practical application. Now, a single-atom tailoring strategy applied to platinum nanowires maximizes their specific and mass activities for the hydrogen evolution and methanol and ethanol oxidation reactions.

Axially chiral compounds have proven to be privileged catalysts/ligands for asymmetric catalysis, with BINOL, SPNIOL and their derivatives being particularly successful. Here the authors report a family of axially chiral alkenes, and demonstrate their use in asymmetric catalysis.

The availability of Lewis antigens allows the investigation of their important biological functions, but site-specific fucosylation for their synthesis is challenging. This work reports an enzymatic platform for the synthesis of complex Lewis antigens, offering an opportunity to explore the Lewis antigen related glycome.

Primary alcohols are known for their broad application in life sciences and the chemical industry. Now, Beller and colleagues present a regioselective, iron-catalysed hydrogenation of aliphatic and aromatic epoxides as a general route to primary alcohols under mild conditions

The reduction of alkynes to alkenes is complicated by the potential for over-reduction to the alkane. Here, for the iridium-catalysed semi-hydrogenation of alkynes, the endpoint of the reaction is clearly identified by a colour change of the metal complex.

Detailed knowledge about its catalytic process is important for exploiting [Fe]-hydrogenase—an enzyme that cleaves and produces H₂—for technological purposes. This study presents an atomic-resolution crystal structure of a substrate-bound closed active form of the enzyme and a precise catalytic cycle.

DNAzymes are attractive catalysts for biomedical and biotechnological applications, but their catalytic mechanism remained obscure. This work investigates the detailed reaction mechanism of RNA ligation catalysed by the 9DB1 DNAzyme, revealing that it resembles those of natural protein enzymes.