Reviews & Analysis

Making chiral molecules by C–H bond activation using inexpensive, earth-abundant metal catalysts is challenging. Now, a cobalt salt combined with a salicyl-oxazoline ligand enables a C–H activation and annulation process and the introduction of axial chirality around a C–N bond.

For 3D printing to reach its full potential, materials should be designed to take advantage of the unique processing flows involved. In this Perspective, we explore the design rules for printable materials and articulate how 3D printing can direct and enhance the functionality of printed systems.

Inspired by catenane chemistry, mechanically interlocked plasmonic nanostructures are synthesized in a bottom-up approach. The nanocatenanes exhibit mechanical helical chirality and, when combined with a thermoresponsive polymer, can actuate mechanical motion.

Polar effects permeate radical chemistry and control the outcome of radical reactions. This Review discusses important types of polar effects and how their interplay has been used in the synthesis and late-stage modification of complex molecules. The discussion covers hydrogen-atom transfer, halogen-atom transfer and homolytic aromatic substitution.

MXenes are 2D materials with a rich chemistry and applications in energy storage, electronics and biomedicine. This Review discusses various MXene syntheses—from layered precursors to single-layer 2D flakes—including principles behind these methods and synthesis–structure–property relationships.

Metal-catalysed asymmetric allylic alkylations are now well established in natural product synthesis. When applied to butenolides, this reaction has always produced the C3-allylated products rather than the C5-allylated analogues. A method is introduced that provides a switch in regioselectivity and enables straightforward access to butenolide-containing natural products with complete stereocontrol.

A strategy to synthesize allenylphosphine derivatives with both P and axial chirality is developed and allows for diverse derivatizations of chiral phosphines. The Ni-catalysed enantioconvergent reaction occurs without racemization or symmetrization of the propargylic carbonate substrate, as demonstrated by combined experimental and computational methods.

Noble metal chalcogenides are rapidly becoming attractive materials in several areas of nanoscience; however, their synthesis remains challenging. Now, a simple cation exchange protocol has been employed to prepare these materials in various phases and morphologies.

Nature has evolved several biosynthetic CO₂ fixation pathways for the conversion of CO₂ into multi-carbon molecules. Now, a synthetic acetyl-CoA bi-cycle is reported that offers increased carbon efficiency by rewiring carbon fixation and non-oxidative glycolysis with implications for industrial gas fermentation.

Metals in their zero-valent form offer a great deal of potential for chemical synthesis. The reliable and straightforward activation of these raw materials has perhaps inhibited the full realization of this promise. This review examines the emergence of the technique of ball milling as a reactor technology to enable mechanical activation of zero-valent metals.

Catalytic intramolecular C–H amination via nitrene transfer typically yields N-heterocycles which can be unmasked to amino alcohols and diamines. Now, an enantioselective Co-catalysed 1,5-C–H amination to form cyclic sulfamidates from alcohols allows for ring opening to deliver diverse β-functionalized chiral amines.

The current production of bulk chemicals often requires constant high temperatures. Now, Joule heating using electricity can be harnessed by imposing temperature modulation on reactions. By optimizing timescales, reaction selectivity and catalyst stability is improved.

The relationship between synthetic discoveries and the materials breakthroughs that they enable is explored in this Perspective. It is concluded that most materials breakthroughs involve chemical compounds that were made out of curiosity or for an entirely different purpose. This conclusion has implications for the role of exploratory synthesis in materials research.

By combining the link of a catenane with the interweaving of a trefoil knot, a molecular structure with a double knot-link containing 14 crossings is prepared. The knot-link contains two homochiral trefoil knots that are quadruply linked with each other.

Crystal engineering of nanosized and hierarchical zeolites may improve the mass transport properties of materials at the nanoscale in various applications. In this Review, synthetic methods used to prepare different classes of zeolitic materials are summarized, with a focus on nucleation and growth mechanisms. Experimental and computational advances, as well as future challenges in the field, are discussed.

Scalable and efficient chemical recycling of commodity polymeric materials remains a challenge as the materials continually accumulate in the environment. Now, upcycling of polystyrene into benzoic acid and other value-added chemicals is realized under mild photooxidation conditions, with hydrogen atom transfer as the key step.

Nickel-catalysed cross-electrophile coupling (XEC) is a useful reaction in synthetic organic chemistry. Now, a nickel-catalysed electrochemical XEC reaction mediated by dynamic ligand exchange enables the formation of a C(sp²)–C(sp³) bond between tertiary alkyl bromides and aryl (pseudo)halides.

Accessing reactive ketyl-type radicals in mild and controllable ways represents an ambitious target. A study now reports a multicomponent palladium-photocatalysed reaction between aldehydes, 1,3-butadiene and various nucleophiles that affords complex homoallylic alcohols through ketyl-type radicals.

Catalytic asymmetric transformations of quinone methides and indole imine methides involve catalysts such as chiral Brønsted acids, Lewis acids and bases as well as transition metal complexes. In this Review, these asymmetric transformations are discussed with a focus on reaction pathways and activation modes.

Alkaline earth elements are among the most abundant and cost-effective metals in the toolbox of synthetic chemists and investigations of their structures and bonding have led to fascinating discoveries. This Review discusses the emerging synthetic chemistry and unusual redox chemistry of low-oxidation-state Be, Mg and Ca complexes.