Nature Catalysis最新文献

Multicomponent cross-coupling reactions involving alkenes represent a compelling strategy for accessing three-dimensional molecules, a key pursuit in contemporary medicinal chemistry. Transition metal-catalysed processes predominantly necessitate the use of conjugated alkenes or non-activated alkenes equipped with specific auxiliary functional groups, for example, 8-aminoquinoline. However, it remains a huge challenge to directly use unmodified native functional groups, such as alcohols and ethers, as directing groups. Here, by utilizing an anionic bidentate ligand such as acac, we have successfully addressed the challenge of employing weakly coordinating native functional groups as directing groups in a nickel-catalysed cross-coupling of non-activated alkenes. This reaction enables the simultaneous introduction of an sp² fragment and an sp³ fragment to two carbons of the alkenes with high chemo- and regioselectivity. This work demonstrates the advantages and potential of anionic bidentate ligands in the cross-coupling of non-activated alkenes.

The increasing popularity of four-member rings in drug discovery has prompted the synthetic chemistry community to advance and reinvent old strategies to craft these structures. Recently, the strain-release concept has been used to build complex architectures. However, although there are many strategies for accessing small carbocyclic derivatives, the synthesis of azetidines remains underdeveloped. Here we report a photocatalytic radical strategy for accessing densely functionalized azetidines from azabicyclo[1.1.0]butanes. The protocol operates with an organic photosensitizer, which finely controls the key energy-transfer process with distinct types of sulfonyl imines. The radical intermediates are intercepted by the azabicyclo[1.1.0]butanes via a radical strain-release process, providing access to difunctionalized azetidines in a single step. This radical process is revealed by a combination of spectroscopic and optical techniques and density functional theory calculations. The power and generality of this method is illustrated with the synthesis of various azetidine targets, including derivatives of celecoxib and naproxen.

While electrochemical nitrate reduction to ammonia represents a promising route for water treatment and ammonia generation, one critical challenge in the field is the need for high-concentration supporting electrolytes in this electrochemical system. Here we report a three-chamber porous solid electrolyte reactor design coupled with cation shielding effects for efficient nitrate reduction reaction without supporting electrolytes. By feeding treated water from the cathode chamber to the middle porous solid electrolyte layer, we can realize an alkali metal cation shuttling loop from the middle layer back into the cathode chamber to boost the nitrate reduction selectivity and suppress the hydrogen evolution side reaction. This reactor system can deliver high ammonia Faradaic efficiencies (>90%) at practical current densities (>100 mA cm⁻²) under a typical wastewater nitrate concentration of 2,000 ppm, enabling a high-purity water effluent and NH₃(g) as products with no need for electrolyte recovery processes.

The activation and transformation of carbon monoxide (CO), a versatile C1 feedstock, continues to attract substantial attention. Traditionally, researchers have focused on the development of catalytic systems to activate CO and then quench the generated acyl intermediate with nucleophiles to complete the carbonylative transformations. Here, non-classically, we unveil a visible-light-induced, carbonylation-triggered radical relay rearrangement reaction, in which the CO insertion step is a key element for functional group migration. The selective insertion of a carbonyl group into the newly generated carbon radical provides a bridge for (hetero)aryl group migration, and the positive feedback of group migration also enables the carbon radical to capture CO more efficiently. A series of 1,4-dicarbonyl compounds containing fluoroalkyl and heterocycles are synthesized successfully under mild conditions, and the conversion of the products to valuable heteroaromatic biaryls indicates the synthetic potential of this platform.

A bias-free photochemical diode, in which a p-type photocathode is connected to an n-type photoanode to harness light for driving photoelectrochemical reduction and oxidation pairs, serves as a platform for realizing light-driven fuel generation from CO₂. However, the conventional design, in which cathodic CO₂ reduction is coupled with the anodic oxygen evolution reaction (OER), requires substantial energy input. Here we present a photochemical diode device that harnesses red light (740 nm) to simultaneously drive biophotocathodic CO₂-to-multicarbon conversion and photoanodic glycerol oxidation as an alternative to the OER to overcome the above thermodynamic limitation. The device consists of an efficient CO₂-fixing microorganism, Sporomusa ovata, interfaced with a silicon nanowire photocathode and a Pt–Au-loaded silicon nanowire photoanode. This photochemical diode operates bias-free under low-intensity (20 mW cm⁻²) red light irradiation with ~80% Faradaic efficiency for both the cathodic and anodic products. This work provides an alternative photosynthetic route to mitigate excessive CO₂ emissions and efficiently generate value-added chemicals from CO₂ and glycerol.