Recycling carbon dioxide (CO2) remains a challenge for long-duration crewed missions, as carbon is an essential element to produce vital resources. This article is a review of the state-of-the-art technologies for removing and recycling metabolically produced CO2 in microgravity environments, including stations, habitats, vehicles, and suits. The study covers the breathable air requirements for astronauts, supply requirements for missions, carbon removal technologies, and synthetic and biological conversion routes from CO2 to fuels, sugars, foods, pharmaceuticals, and materials.

Transient excited-state auxiliaries provide a powerful strategy for enabling difficult bond activations under mild conditions. Here we report a general alcohol oxidation platform in which phenylglyoxalate α-keto esters act as visible-light-activated, traceless oxidation devices, converting primary and secondary alcohols to aldehydes and ketones without external photocatalysts, metals, or stoichiometric oxidants. The protocol shows broad functionalgroup tolerance and supports late-stage oxidation of complex scaffolds, including pharmacophores, carbohydrates, steroids and a peptide. Practicality is further demonstrated through in situ alcohol activation and efficient continuous-flow scale-up. Mechanistic experiments and DFT studies support a photoinduced fragmentation pathway consistent with a 1,5-HAT-initiated biradical process, underscoring the utility of excitedstate α-keto esters as transient, traceless auxiliaries for preparative oxidation chemistry.

Developing nanomaterials that combine excellent dispersibility with high electrical and thermal conductivity performance is essential for next-generation multifunctional composites. Herein, we present a solvent-free, benign-by-design mechanochemical route for synthesizing nitrogen-doped graphene nanoplatelets (N-GNPs) by ball-milling graphite with glycine, an amino acid serving simultaneously as a nitrogen source and exfoliation aid, together with potassium hydroxide as a nucleophile generator. This one-pot process enables simultaneous exfoliation and nitrogen incorporation, producing pyrrolic, graphitic, and pyridinic functionalities, delivering a unique balance of conductivity (30% of Graphite powder) and long-term dispersibility in a range of solvents (up to one month) rarely achieved through conventional functionalization methods. The method could achieve a high yield (similar to 80%) under ambient temperature and pressure, with significantly lower energy demand than conventional approaches. Importantly, the strategy is inherently green: it relies on a bio-based nitrogen precursor, avoids toxic dopants and volatile organic solvents, and outperforms hydrothermal and pyrolytic routes in terms of E-factor and CO2 footprint, thereby aligning strongly with green chemistry principles. As nanofillers in vitrimer composites, N-GNPs impart electrically triggered self-healing, improved mechanical and conductive properties, and significantly faster stress relaxation while maintaining the same topology-freezing temperature (Tv) as the neat vitrimer, enabling multifunctional performance without compromising network stability.

Continuous flow techniques have become important tools for molecular synthesis, both in academia and across the fine chemicals industry. The success of these methods has been in part due to their interdisciplinary nature, bringing together chemists and engineers to design and construct creative solutions for the novel synthesis and scale-up of molecules, with applications in pharmaceuticals, agrochemistry, materials chemistry and crystallization. The advantages of flow chemistry include the high surface-area-to-volume ratio of narrow tubing, which improves temperature control, and the ability to scale by increasing reaction time rather than vessel volume. Further, the use of flow enables improved safety protocols, reduces waste and has the potential to telescope downstream work-up processes. Perceptions of flow chemistry as a field with a high barrier to entry remain, and these techniques have not yet become a standard option for most chemists owing to the lack of exposure in academic settings. To help reduce this barrier, this Primer introduces the field, covering the fundamental considerations of assembling a lab-scale flow experiment, using literature examples to illustrate their practical application. We conclude with an outlook for the field, highlighting opportunities for potential and existing users of the technique alike. Flow chemistry is a synthesis technique that uses pumps, tubing and connectors to control reactions spatially rather than temporally. This spatial control enables faster reaction times, better temperature regulation and higher yields over traditional batch processes, making it advantageous for the synthesis of pharmaceuticals, agrochemicals and advanced materials.

The abundance, structural diversity and versatility of ketones give prominence to this carbonyl functional group in synthetic chemistry. The assembly of ketones via the carbonylative hydroacylation alkenes represents a powerful modular strategy for the synthesis of unsymmetric ketone products. Here, we report the first photocatalytic carbonylative hydroacylation of alkenes with unactivated alkyl halides. This protocol unifies the visible-light multiphoton catalytic cycle of [Ir(ppy)2(dtb-bpy)]+ with flow chemistry to engage energy demanding alkyl bromides and iodides at moderate pressures of carbon monoxide. The mild and practical methodology was employed to prepare a diverse array of 43 unsymmetric dialkyl ketones from primary, secondary and tertiary unactivated alkyl halides. We demonstrate the application of flow chemistry technology to achieve spatially resolved chemoselectivity, scalability and the generation of biologically relevant ketone products.

The modern (petro)chemical industry has supported substantial development but uses unsustainable fossil resources detrimental to the Earth’s ecosystem via climate change and chemical pollution. This commentary highlights how catalysts can support development of critical fuel and chemicals manufacturing using sustainable waste resources to transition the industry from a linear to a circular economy.

Machine-learning assisted optimisation of a continuous photodegradation reaction, using a TiO2 coated catalytic static mixer successfully accounting for catalyst degradation.

Organometallic reagents are routinely used as fundamental building blocks in organic chemistry to rapidly diversify molecular fragments via carbanion intermediates. However the catalytic generation of carbanion equivalents particularly from sp3-hybridized alkyl scaffolds, remains an underdeveloped goal in chemical synthesis. To align with the demands of modern synthetic protocols, a general method for the catalytic generation of alkyl carbanions must operate under benign reaction conditions and access commercially available feedstock chemicals. Alkenes constitute an attractive source of latent alkyl carbanion equivalents, however methods for the conversion of carbon-carbon bonds into carbanions is challenged by the need for precious metals and aggressive stoichiometric reductants. Here we disclose an approach for the controlled generation of 2-electron carbon nucleophiles via single electron reduction of aryl alkenes, facilitated by the highly reducing environment of multiphoton photoredox catalysts. We demonstrate that alkene radical anions engage in catalytic, metal free, intermolecular C-C bond-forming reactions with carbonyl derivatives, in a manner analogous to Grignard reagents. Under this reaction manifold, the alkene can be considered a dicarbanion synthon offering new opportunities for orthogonal diversification. This concept was illustrated by the development of four distinct C-C bond forming reactions with aromatic alkenes: hydroalkoxylation, hydroamidation, aminoalkylation and carboxyaminoalkylation, to generate a range of valuable and complex scaffolds.

The direct coupling of alkene feedstocks with aldehydes represents an expedient approach to the generation of new and structurally diverse C(sp3)-hybridized alcohols that are primed for elaborated into privileged architectures. Despite their abundance, current disconnection strategies enabling the direct coupling of carbon-carbon π-bonds and aldehydes remain challenging because contemporary methods are often limited by substrate or functional group tolerance, and compatibility in complex molecular environments. Here, we report a coupling between simple alkenes, heteroarenes and unactivated aliphatic aldehydes via an electrochemically induced reductive activation of C–C π bonds. The cornerstone of this approach is the discovery of a rapid alternating polarity (rAP) electrolysis to access and direct, highly reactive radical anion intermediates derived from conjugated alkenes and heterocyclic compounds. Our developed catalyst-free protocol enables direct access to new, and structurally diverse C(sp3)-hybridized alcohol products. This is achieved by the controlled reduction of conjugated alkenes and the C2–C3 π-bond in heteroarenes via an unprecedented reductive dearomative functionalization for heterocyclic compounds. Experimental mechanistic studies demonstrate that rAP electrolysis is necessary for the controlled generation of radical anion intermediates and promotes a kinetically biased single-electron reduction of the C–C π-bonds over aldehydes. Overall, this technology provides a versatile approach to the reductive coupling of olefin and heterocycle feedstocks with aliphatic aldehydes, offering straightforward access to diverse C(sp3)-rich oxygenated scaffolds.

Dual nucleophilic phosphine photoredox catalysis is yet to be developed due to facile oxidation of the phosphine organocatalyst to the phosphoranyl radical cation. Herein, we report a reaction design that avoids this event and exploits traditional nucleophilic phosphine organocatalysis with photoredox catalysis to allow the Giese coupling with ynoates. The approach has good generality, while its mechanism is supported by cyclic voltametric, Stern-Volmer quenching, and interception studies.

University–industry (U–I) collaboration takes on many forms, from research services, teaching and training, to curiosity-led research. In the chemical industries, academic chemists generate new knowledge, address novel problems faced by industry, and train the future workforce in cutting-edge methods. In this study, we examine the dynamic structures of collaborative research contracts and grants between academic and industry partners over a 5-year period within a research-intensive Australian university. We reconstruct internal contract data provided by a university research office as records of its collaborations into a complex relational database that links researchers to research projects. We then structure this complex relational data as a two-mode network of researcher-project collaborations for utilisation with Social Network Analysis (SNA)—a relational methodology ideally suited to relational data. Specifically, we use a stochastic actor-oriented model (SAOM), a statistical network model for longitudinal two-mode network data. Although the dataset is complicated, we manage to replicate it exactly using a very parsimonious and relatable network model. Results indicate that as academics gain experience, they become more involved in direct research contracts with industry, and in research projects more generally. Further, more senior academics are involved in projects involving both industry partners and other academic partners of any level. While more experienced academics are also less likely to repeat collaborations with the same colleagues, there is a more general tendency in these collaborations, regardless of academic seniority or industry engagement, for prior collaborations to predict future collaborations. We discuss implications for industry and academics.

The abundance, structural diversity, and versatility of ketones give prominence to this carbonyl functional group in synthetic chemistry. The assembly of ketones via the carbonylative hydroacylation of alkenes represents a powerful modular strategy for the synthesis of unsymmetric ketone products. Here, we report the photocatalytic carbonylative hydroacylation of styrenes with unactivated alkyl halides. This protocol unifies the visible-light multiphoton catalytic cycle of [Ir(ppy)(2)(dtb-bpy)](+) with flow chemistry to engage energy-demanding alkyl bromides and iodides at moderate pressures of carbon monoxide. The mild and practical methodology was employed to prepare a diverse array of 44 unsymmetric dialkyl ketones from primary, secondary, and tertiary unactivated alkyl halides. We demonstrate the application of flow chemistry technology to achieve spatially resolved chemoselectivity and broad functional group tolerance for the mild generation of functionalized C(sp(3))-rich ketone products.

Visible light induced singlet nucleophilic carbene intermediates undergo rapid [2+1]-cycloaddition with tethered olefins to afford unique bicyclo[3.1.0]hexane and bicyclo[4.1.0]heptane scaffolds. This cyclopropanation proceeds using only visible light irradiation, circumventing the use of exogenous (photo)catalysts or sensitisers and showcases an underexplored mode of reactivity for nucleophilic carbenes in chemical synthesis. The discovery of additional transformations including a cyclopropanation/retro-Michael/Michael cascade reaction to afford chromanone derivatives are also described.

Reported here is a regioselective C(sp3)–C(sp2) cross coupling reaction between inert γ-C(sp3)–H bonds in aliphatic amines and cyanoarenes under electrochemical conditions in flow. The developed methodology takes advantage of a removable redox active auxiliary, which triggers selective 1,7-hydrogen atom transfer to functionalise an aliphatic C–H bond at the γ-position of an alkyl amine. In this reaction, a cyanoarene radical anion functions as both a selective arylating reagent and a redox active mediator, enabling the controlled one electron reduction of the redox active auxiliary. This strategy offers a new approach towards γ-C(sp3)–H bond functionalisation allowing generation of, amongst others, sterically crowded carbon centres under mild reaction conditions and in the absence of additional catalysts or radical initiators.

Two dimensional (2D) sheets of graphene/graphene oxide are the building blocks of a wide range of material architectures with strong application potential in energy storage and harvesting, and environmental remediation. A consistent issue with continuous 2D sheets, especially when hundreds of such 2D sheets are stacked tightly to form films and electrodes, is their low mass transport characteristics through the assembled structure. To overcome this problem, we report a sequential, two-step photochemical technique comprising nucleation of defects on 2D nanosheets of graphene/graphene oxide by long-wavelength (UVA/UVB) irradiation, followed by the growth of nanopores in H2O2-based etching triggered by short-wavelength (UVC) irradiation. We demonstrate our ability to tailor the size (10- 100 nm) and level of porosity (16-60%) in holey graphene oxide (h-GO). To test the holey GO we synthesized, we produced the nanofiltration membranes using h-GO with different pore sizes. Membranes made from hGO nanosheets with similar to 60 nm pores exhibited up to a 3.7-fold increase in water permeance and an similar to 10% increase in selectivity compared to those produced by pristine GO. We attribute this unusual behavior to the presence of water transport highways (the nanopores) and a smaller interlayer distance of the hGO sheets arising from a complex balance in hydroxylation and deoxygenation reactions during the photochemical process. We demonstrated successful transition of the method to a flow-based synthesis approach with highly enhanced production rates (similar to 188 mg/h, an about 30-fold increase over the batch process), thereby accelerating sustainable and automated manufacturing of perforated graphene materials and their adoption in industrial uses.

In this work, copper (Cu) decorated indium oxide (In2O3) rods were prepared via a simple wet chemistry method under mild temperature at atmospheric pressure. The resultant copper decorated indium oxide (Cu/In2O3) composites showed changes in the morphology, composition, crystal property, oxidation status, optical property, and textural surface properties. The In2O3 rods showed highly catalytic efficiency in reducing CO2 to CO, H-2 and CH4 in the presence of water via a photocatalytic mechanism under simulated sun light. Incorporation of copper significantly increased the total conversion rates and regulated the selectivity. Total evolution rates of carbon-based products (CO and CH4) for Cu/In2O3 with different Cu content were all greater than 1 mmol.gcat(-1).h(-1). In addition to the high efficiency, copper addition also enhanced the selectivity towards forming carbon-based products (CH4 and CO), even amounting to 100% for 20% target copper addition. This low-cost preparation method, paired with high CO2 photoreduction efficiency and selectivity, has the potential for future industrial applications of these new Cu/In2O3 composites.

In a first of its kind, we are delighted to present a collection of papers that showcase the high-quality work of internationally recognised Australian and New Zealand researchers in the early stages of their independent careers.

The development of a flow-assisted synthesis of alkyl citrate natural products is described. The flow route harnesses a number of steps including the generation of ketene silyl acetal, a formal [2 + 2] cycloaddition, and a methanolysis cascade to efficiently generate a highly substituted, and stereodefined tetrahydrofuran intermediate. A heterogeneous pseudo-Finkelstein reaction and zinc-mediated elimination furnish a key alkene alkyl citrate fragment in high yield over a multistep sequence that provides direct entry to compounds such as (-)-CJ-13982 (1), (-)-CJ-13,981 (2), L-731,120 (3), and related natural products. The flow methodology developed in this study enables a new machine-assisted approach toward the efficient and scalable synthesis of the alkyl citrate family of natural products.