Volume 1 Issue 8, August 2018

Metalloprotein activity can be tuned by altering first- and second-sphere interactions with the metal ion or ions. Here, a non-canonical haem axial ligand is introduced into a myoglobin variant, modulating both. The resulting enhancement of cyclopropanation activity illustrates the utility of expanding the suite of available amino acids for biocatalyst engineering.

The chemical synthesis of natural products, such as sesquiterpenes, is a daunting task due to their complexity and precise functionalization, and multiple synthetic and purification steps that reduce overall yields are usually required. Now, a highly efficient alternative approach using supramolecular chemistry has been proposed by Tiefenbacher and co-workers.

How the first metabolic network was organized to power a cell remains an enigma. Now, simple iron–sulfur peptides have been used to generate a pH-gradient across a protocell membrane by catalysing hydrogen peroxide reduction. This indicates that short peptides could have fulfilled the role of redox active metalloproteins in early life.

The histidine brace found in certain copper oxidases enables the oxidation of strong C–H bonds in organic substrates. This Perspective highlights and discusses the possible structural and electronic features of this motif and how these features underlie its role in challenging oxidative catalysis.

A haem–carbenoid has been proposed to be involved in abiological enzymatic reactions. Now, Hilvert and co-workers provide crystallographic evidence for a haem–carbenoid intermediate as the reactive species in an olefin cyclopropanation reaction catalysed by an artificial metalloenzyme.

Though pentamethylcyclopentadienyl rhodium(iii) complexes have been successfully employed for C–H functionalizations, stereocontrol can be difficult due to the lack of vacant coordination sites on the metal centre. Here, Yoshino, Matsunaga and co-workers show that chiral anions can be used alongside the achiral rhodium complex to catalyse C–H activation and subsequent asymmetric conjugate addition.

The efficient design of electrochemical CO₂ reduction catalysts requires high CO₂ concentrations on the catalyst surface. Here, Cui and co-workers make use of flexible, hydrophobic, nanoporous polyethylene membranes with good gas permeability to design a catalytic set-up that mimics the alveolus structure in mammalian lungs, achieving high activity and selectivity to CO.

Prenylation is a common step in the synthesis of many natural products, and enantioselective variants require the use of enzymatic catalysts. Now, You and co-workers report a palladium phosphoramidite catalyst capable of enantioselective, dearomative prenylations across a broad range of starting materials, and demonstrate its power in a number of natural product syntheses.

The synthesis of complex terpene compounds in the laboratory using man-made catalysts has proven to be much more complicated than in nature. Now, Tiefenbacher and co-workers report the use of an enzyme-mimicking supramolecular catalyst for the efficient and short synthesis of tricyclic sesquiterpenes.

The bioenergetic metabolism of all life today depends on proton gradients; however, it remains unclear how such gradients developed in early life. Here, Mansy and co-workers establish a possible prebiotic mechanism in which iron–sulfur peptide redox networks generate a trans-membrane pH gradient.

The synthesis of nanocatalysts with small dimensions and high surface-to-volume ratios is of great interest to lower catalyst costs and exploit catalytic performance enhancements through size effects. Now, Prinz and colleagues show that two-dimensional growth of platinum nanoparticles with suppressed thicknesses can be promoted with passivation-gas-incorporated atomic layer deposition.