Volume 3 Issue 3, March 2024

Using a fully automated closed-loop system, a robotic chemist synthesizes an oxygen-evolution catalyst from Martian meteorites, with implications for the production of catalysts that may underpin human survival on Mars in the future.

Strained allenes in piperidines and tetrahydropyrans are used to generate highly-decorated heterocycles.

A homologative process that enables vinylene insertions into organoboronates stereoselectively forms alkenyl boronates.

Acid triggers the formation of radicals by Flory autoinitiation of acrylic monomers and enhances polymerization rates.

Palladium-catalysed enantioselective α-arylation of azlactones and 5H-oxazol-4-ones with aryl halides using Sadphos ligands enables the synthesis of α-aryl quaternary amino acids and glycolic acid derivatives.

Molecular knots and links retrofitted with iminopyrrole units make these assemblies intrinsically flexible, strengthening their potential application in molecular machinery.

Since the isolation of a Mg–Mg complex, research on low-oxidation-state s-block chemistry has flourished. An approach to forming metal–metal bonds between Mg and the heavier alkaline earth metals (Ca, Sr and Ba) is now demonstrated. The unusual electronic nature of these compounds could stimulate further discussions of metal–metal bonding.

Modular access to nimbolide could provide the opportunity to develop agents that target poly-ADP-ribose polymerase 1 (PARP1) for the treatment of BRCA-deficient cancers. Now, a convergent strategy is reported, in which late-stage coupling of a pharmacophore-containing building block and a diversifiable hydrazone unit enables the preparation of nimbolide and various analogues.

Rapid, long-distance transport of an ultrathin and uniform palladium film on a two-dimensional (2D) crystal of tungsten ditelluride at accessible temperatures is reported. The surprising effect is generalizable and offers possibilities for exploring chemical synthesis in nanoconfined spaces and access to not yet synthesized 2D materials.

The visible-light-driven thiolate-catalysed carboxylation of C(sp²)–H bonds in azines using CO₂ is demonstrated. This procedure can be applied to various azine substrates to obtain a range of N-heteroaromatic carboxylic acids with different functionalities, including bioactive molecules and carboxylated N-ligands.

Metal–organic framework (MOF) materials are promising photocatalysts for solar-driven fuel production from CO₂. Here, built on a literature survey and data macroanalysis, we examine the development of MOFs as photocatalysts for CO₂ conversion, while assessing pitfalls and opportunities.

Sustained Mars exploration requires in situ synthesis of vital chemicals such as oxygen. Now a data-driven platform for synthesizing oxygen-producing electrocatalysts from Martian meteorites using robotics and artificial intelligence is developed, allowing automated screening of the optimal catalyst formula. This approach demonstrates materials discovery under challenging circumstances and without human intervention.

Strained cyclic allenes are short-lived intermediates that confine a functional group with a preferred linear geometry, an allene, into a small ring, inducing strain-driven reactivity. Now, 2,3-azacyclic and 2,3-oxacyclic allenes are generated and trapped using cycloaddition reactions, generating complex heterocycles that bear a large fraction of sp³-hybridized atoms.

Homologation of organoboronates by iterative carbenoid insertion is an effective method for the synthesis of alkyl chains, but the corresponding homologation using vinyl units remains elusive. Now, a stereoselective vinylene homologation reaction is reported, comprising diastereoselective successive insertion of silyl- and alkoxy-substituted carbenoids into organoboronates, followed by a Peterson-type elimination.

Acid-triggered reversible addition–fragmentation chain-transfer polymerizations, in the absence of conventional initiating species and in the dark, are reported to prepare polymers with low dispersity and high end-group fidelity. The protonation of monomers catalyses both the initiation and propagation steps and can also be applied to free radical polymerizations.

Chiral α-quaternary amino and glycolic acids have found use in medicinal applications. Although their synthesis through α-alkylation is well known, synthesis via α-arylation remains challenging. Now, palladium-catalysed methods for the enantioselective α-arylation of amino acid- and glycolic acid-derived heterocycles, azlactones and 5H-oxazol-4-ones, using aryl bromides, are reported.

Cation–anion exchange between dimers to prepare mixed aggregates with Mg–Ae (alkaline earth) bonding (Ae = Mg, Ca, Sr, Ba) is reported. Considerable electron transfer from the (BDI)Mgˉ anion (BDI, β-diketiminate) to Ae and Na atoms is observed, and the reactivity of these electron-rich complexes with Na–Mg–Ae bonding is discussed.

Nimbolide is an inhibitor of poly(ADP)-ribosylation-dependent ubiquitin E3 ligase RNF114. A modular synthesis of nimbolide and its analogues is now reported, using a sulfonyl hydrazone-mediated etherification and a radical cyclization strategy. These analogues give insight into structure–activity relationships and some have superior poly(ADP-ribose) polymerase-1 trapping activity relative to nimbolide.

The unexpected phenomenon of rapid, long-distance transport of an ultrathin and uniform metal film on two-dimensional crystals is reported at temperatures well below the melting points of all of the materials involved. The effect is generalizable and may offer possibilities in confined space chemistry, as well as in two-dimensional crystal growth and devices.

The catalytic carboxylation of C(sp²)–H bonds using CO₂ is an efficient strategy to produce carboxylic acids; however, the carboxylation of azines is a challenge. Now, a visible-light-driven, thiolate-catalysed method for the carboxylation of azine C(sp²)–H bonds using CO₂ is reported, enabling the synthesis of N-heteroaromatic carboxylic acids with excellent regiocontrol.

Low-selectivity photocatalytic carbon dioxide reduction has been overlooked, due to the difficulty in separating and utilizing the mixed products. Now, a triple tandem strategy is reported to convert the mixed reduction products, H₂ and CO, sequentially into olefinic and carbonyl fine compounds with high atom utilization efficiency.