Articles in 2022

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.

The performance of single atom catalysts (SACs) is controlled by the metal single atom sites, but the role of the matrix material is less understood. Now, a hard-template synthesis is reported, enabling control of the atomic and mesoporous structures of SACs and the probing of matrix materials with either 2D or 3D diffusion channels.

Functionalization of C–H bonds through direct hydrogen atom transfer (HAT) photocatalysis is an attractive synthetic reaction; however, many methods suffer from low catalytic efficiency. Now, the efficiency of direct HAT photocatalysis using photocatalyst eosin Y combined with Brønsted acids is reported, enabling the functionalization of unactivated C(sp³)–H bonds.

Inspired by molecular catenanes, mechanically interlocked gold nanocatenanes are synthesized starting from triangular gold nanoplates. The interlocked gold nanocatenanes have intriguing optical and mechanical properties, originating from their plasmonic nanomechanical bonds.

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.

The construction of C–C bonds with regio- and stereoselectivity is paramount in natural product synthesis and metal-catalysed asymmetric allylic alkylation reactions have played a key role, with high C3 selectivity demonstrated in butenolide synthesis. Now, a palladium-catalysed C5-selective method is reported, providing direct and highly enantioselective access to a range of diversely substituted butenolides.

The synthesis of P-stereogenic allenylphosphine derivatives is often long or requires preformed P-stereogenic substrates. Now, a one-step enantioconvergent synthesis of allenylphosphines with both P and axial chirality is reported. The process proceeds through a Ni^II-catalysed propargylic substitution of secondary phosphines, without racemization or symmetrization of the racemic propargylic carbonates, to give P-stereogenic allenylphosphines.

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.

The synthesis of noble metal chalcogenides (NMCs) in a well-controlled manner remains challenging. Now, a robust and versatile strategy for the preparation of a wide variety of NMCs via cation exchange is demonstrated and the generality of this strategy is validated by the synthesis of NMCs with tailored morphologies and compositions.

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.

Atroposelective synthesis of C–N axially chiral anilides typically requires preformed aromatic ring systems. Now, a cobalt-catalysed atroposelective C–H activation and annulation method to construct isoquinolinones from benzamides, with C–N axially chirality, is reported. Using a chiral salicyl-oxazoline ligand and O₂ as an oxidant, the method yields isoquinolines in excellent yields and enantioselectivities.