Volume 14 Issue 6, June 2022

In early 2020, Shira Joudan was in the final stages of her PhD when the COVID-19 pandemic hit. Despite the challenging circumstances, she graduated, found a postdoc position and will begin her independent academic career in early 2023.

Being able to run two reactions concurrently enables synthetic methods to be streamlined, but simultaneously controlling the selectivity of both reactions is an enormous challenge. Now, a directing group is used to reinvent a classic tandem reaction, activating specific sp³ C–H bonds with pinpoint accuracy.

Trisubstituted macrocyclic alkenes are prominent moieties in natural products, and although ring-closing metathesis reactions can be used to access such targets, the yields are typically suboptimal and the stereochemical outcome is unpredictable. Now, a methodology has been developed that tackles both of these challenges.

Explaining the controlled emergence and growth of molecular complexity at life’s origins is one of prebiotic chemistry’s grand challenges. Now, it has been shown that we can observe how the self-organization of a complex carbohydrate network can be modulated by its environment.

The emerging field of dissipative DNA nanotechnology aims at developing synthetic devices and nanomaterials with life-like properties such as directional motion, transport, communication or adaptation. This Review surveys how dissipative DNA systems combine the programmability of nucleic-acid reactions with the consumption of energy stored in chemical fuel molecules to perform work and cyclical tasks.

Nickel-rich layered oxides, such as NCM622, are promising cathode materials for lithium batteries, but chemo-mechanical failures hinder their practical application. Now the solid-state synthesis of NCM622 has been studied using multiscale in situ techniques, and kinetic competition between precursor decomposition and lithiation has been observed to lead to spatially heterogeneous intermediates and the formation of defects that are detrimental to cycling.

The process by which life arose using information from the prebiotic environment and inherent molecular reactivity is unclear. Now, it has been shown that systems of chemical reactions exhibit well-defined self-organization in varying environments, providing a potential mechanism for chemical evolution processes that bridge the gap between prebiotic building blocks and life’s origin.

The regioselectivity of tandem isomerization/hydrocarbonylation reactions is typically dictated by thermodynamics and there are limitations on the isomerization of internal alkenes. Now, it has been shown that a low-valent-tungsten catalyst controls the isomerization of alkenes to classically challenging unactivated internal positions and, with the aid of a directing group, enables subsequent addition of hydrogen and carbon monoxide.

Many bioactive compounds are trisubstituted macrocyclic alkenes, but use of current methods often results in poor yields and low stereoselectivity. Now, a ring-closing metathesis strategy has been developed that enables these compounds to be prepared efficiently and in either stereoisomeric form: an approach that may prove useful in the late stages of total syntheses, for skeletal editing and in drug discovery.

Soft bioelectronic devices have exciting potential applications in robotics, computing and medicine, but they are typically restricted by the requirement for tethers or stiff electrodes. Now, a synthetic nerve has been developed that is bioinspired, wireless and powered by light. By patterning functionalized lipid membrane compartments, information was directionally conveyed using electrochemical signals.

The collision dynamics between a pair of aligned molecules in the presence of a scattering resonance provide the most sensitive probe of the long-range anisotropic forces important to chemistry. By simultaneously controlling the collision temperature and geometry between a pair of aligned D₂ molecules, we unravel the anisotropic dynamics of a cold scattering process.

Molecular energy transfer is thought to follow a simple rule of thumb: high energy transfer requires hard collisions that result in backscattering. However, now it has been observed that an unexpected forward scattering occurs in NO–CO and NO–HD collisions even for high energy transfer. This is attributed to ‘hard-collision glory scattering’, a mechanism that appears to be ubiquitous in molecule–molecule collisions.

In a similar fashion to its macroscopic counterpart, molecular gearing is a correlated motion of intermeshed molecular fragments against one another. Now it has been shown that photogearing can be used to actively fuel molecular gearing motions with light and concomitantly shift the axis of rotation.

A reduction reaction is usually equated with an electron transfer reaction. Now, ultrafast time-resolved serial femtosecond X-ray crystallography has enabled the visualization of the stepwise structural changes that occur after electron transfers have been observed in the light-triggered reduction of flavin adenine dinucleotide catalysed by DNA photolyase.

Most chemical glycosylation methods operate by acid-promoted, ionic activation of donors. Now, by exploiting the formation of a halogen-bond complex, the activation of glycosyl donors was achieved via a visible light-promoted radical cascade process, resulting in a general, simple and mild way to build challenging 1,2-cis-glycosidic bonds.

2D–2D heterostructures are typically held together by van der Waals interactions. Now, an on-device MoS₂–graphene heterostructure has been prepared that is covalently linked through a bifunctional molecule featuring a maleimide and a diazonium group. The electronic properties of the resulting heterostructure are shown to be dominated by the molecular interface.

Entomopathogenic nematodes carrying Xenorhabdus and Photorhabdus bacteria prey on insect larvae in the soil. Now, a comprehensive analysis of the bacterial genome has revealed ubiquitous and unique families of biosynthetic gene clusters. Evaluation of the bioactivity of the natural products expressed by the most prevalent cluster families explains the functional basis of bacterial natural products involved in bacteria–nematode–insect interactions.

The tris(2,2′-bipyridine)ruthenium(II) cation, or ‘rubipy’ to its friends, has had a significant influence on our understanding of the photophysics of transition metal complexes, and has also helped revolutionize organic photochemistry, explains Daniela M. Arias-Rotondo.