Volume 1 Issue 3, March 2022

‘Solar chemical’ production can be limited by the need for sacrificial reagents, metal-containing catalysts and low product values. Now, H₂O₂ is generated from H₂O and air using lignin as a photocatalyst. Combining lignin with enzymatic catalysis enables selective oxyfunctionalization.

By showcasing the activating effect of using alkali-metal alkoxides as additives with polar organometallic reagents, this Perspective outlines applications of these mixed-metal combinations for arene functionalization via metal/halogen exchange and deprotonative metallation. Our mechanistic understanding of how these systems operate has revealed their complex and diverse mixed-metal/mixed-aggregate composition.

Cascade dearomative cyclization reactions are an important subclass of catalytic asymmetric dearomatization reactions, for the synthesis of polycyclic scaffolds. In this Review, cascade asymmetric dearomative cyclization reactions which are catalysed by transition-metal complexes are discussed, with a focus on the cyclization of indoles and related heteroaromatic compounds.

The pulp and paper industry produces approximately 50 million metric tons of lignin per year as a waste product. Here, lignin is shown to act as a photocatalyst for the solar-driven synthesis of hydrogen peroxide from H₂O and O₂ under visible light. Coupling this photocatalytic process with unspecific peroxygenases enables the enantioselective oxyfunctionalization of C–H bonds.

Derivatives of fluorinated alkenes are commonly found in biologically active molecules, but their synthesis remains challenging. Towards this goal, a rhodium-catalysed method for the selective β- or γ-addition of nucleophiles to gem-difluoroallenes has now been developed. Catalysts with N- or P-based ligands result in the β- or γ-selective addition, respectively, of amines and thiols to gem-difluoroallenes.

C-glycosides form the basis of numerous therapeutic compounds, but their synthesis using sustainable catalysts is a challenge. Here, an iron-catalysed reductive cross-coupling method is developed that couples glycosyl radicals, generated in situ from glycosyl chlorides, with unsaturated electrophiles. Mechanistic experiments indicate that the active catalytic species is a low-valent iron complex.

The fabrication of single-metal-atom chains in an atomically precise way is challenging. Now, a chemical vapour co-deposition method is reported for the synthesis of highly ordered single-atom chains of platinum with lengths of up to 20 nm on a wafer-scale. The metallic behaviour of the single-metal-atom chain is revealed by electronic measurements, first-principle calculations and complex network modelling.