Articles in 2022

The construction of seven-membered carbocycles through cycloaddition reactions represents a longstanding challenge in organic synthesis. A study now reports a copper-catalysed enantioselective (4 + 3) cycloaddition between 2-aminoallyl cations and dienol silyl ethers that affords structurally diverse cycloheptanoids with high stereoselectivities and shows broad substrate scope.

α,α-Dideutero carboxylic acids are common precursors for isotopically labelled molecules; however, their synthesis often requires high temperatures with strong bases or precious metals. Now, the α-deuteration of carboxylic acids has been developed under mild conditions using a ternary catalyst system of K₂CO₃, pivalic anhydride and 4-dimethylaminopyridine.

Current synthesis of 2D crystalline superconductors mainly limits them to layered materials. Now, crystalline, non-layered 2D PdTe has been synthesized by inducing interfacial reactions at a solid–solid interface, exhibiting 2D superconductivity with a thickness-dependent onset critical temperature of ~2.56 K.

Synthesis of seven-membered carbocycles via (4 + 3)-cycloaddition reactions is often challenging due to the instability of the zwitterionic three-carbon component required. Now, a copper-catalysed enantioselective (4 + 3)-cycloaddition of 2-amino cations with dienol silyl ethers is reported, providing seven-membered carbocycles in good yields and with excellent enantiocontrol.

Anion-binding interactions are prevalent in nature but not commonly used in polymerizations. Now, an anion-binding catalytic strategy for living cationic polymerization is reported. Selenocyclodiphosph(V)azanes act as hydrogen-bond donors to reversibly activate dormant covalent bonds, and enable control of the equilibrium between the dormant and active species, which ensures precision polymer synthesis.

Heteroepitaxial growth of single-crystal films typically requires stringent matching of the specific lattice ordering with the underlying substrate. Now, amorphous MoTe₂ thin films are shown to transform into wafer-scale 2D single-crystals through seeded growth on the surface of any arbitrary substrate.

Controlling the enchainment of ether and carbonate segments during copolymerization of CO₂ and epoxides is rarely possible. Now, precise control of enchainment is realized by tuning the structure of an organoboron catalyst and the reaction conditions. Mechanistic and computational studies probe the origin of the unique ABB microstructure of the polymer.

Dual-atom catalysts show potential for complex reactions, but their controllable preparation is challenging. A method to transform a Ni nanoparticle into a Ni₂N₆ dual-atom structure on a carbon support yields a catalyst with precisely controlled atomic site distances, giving excellent performance for CO₂ electroreduction.

Dual-atom catalysts are promising for CO₂ reduction reactions; however, sluggish kinetics limit practical applications. Now, a Ni dual-atom catalyst has been synthesized, realizing efficient electrocatalytic CO₂ reduction with a CO partial current density of ~1 A cm² at >99% Faradaic efficiency.

Targeting 2D heterolayers by vertically stacking chemically different layers is a synthetic challenge. A generic and effective approach for synthesizing heterolayered oxychalcogenides using molten hydroxides as unconventional reaction media is introduced. This approach enables the rapid stacking of oxide and chalcogenide layers with precise control of the composition.

Adding a promoter to a catalytic reaction can dramatically alter the performance and reactivity of a chemical transformation. By incorporating a Brønsted acid promoter to a photocatalysed reaction, previously unreactive C–H bonds can be functionalized, enabling the discovery of drug molecules.

[10]annulene derivatives are typically non-planar and non-aromatic, with aromatic planar variants suffering from kinetic instability. Now, the synthesis of a planar and aromatic dehydro[10]annulene featuring a fused cyclopropane and an internal alkyne is reported. The resulting hydrocarbon is bench stable and can be stored for extended periods of time.

The integration of two-dimensional semiconductors and arbitrary materials or architectures offers the possibility to enhance the functionality of a material and improve device performance. Now, a general synthesis route is reported for heteroepitaxial growth of semiconducting 2H-MoTe₂ films on arbitrary single-crystal substrates and three-dimensional architectures without the limitation of lattice matching and a planar surface.

Preparing two-dimensional heterolayers by vertically stacking chemically different layers with multiple anions remains challenging. Now, a general approach for the synthesis of heterolayered oxychalcogenides using molten hydroxides as unconventional solutions for the rapid stacking of oxide and chalcogenide layers with precise composition control is demonstrated.

Quantum chemical calculations can not only provide mechanistic insight into known chemical reactions, but can also be used to predict the outcome of unknown reactions. In silico reaction screening with difluorocarbene is showcased, leading to new multicomponent dearomative cycloaddition reactions of pyridines that provide medicinally important fluorinated N-heterocycles.

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.

Quantum chemical calculations are typically used in synthetic organic chemistry to probe reaction mechanisms and propose stereochemical models. Now, a strategy to develop chemical reactions using quantum chemical calculations is reported. This study demonstrates in silico reaction screening with difluorocarbene, leading to a method for the synthesis of fluorinated N-heterocycles.

The ability to make precise materials rapidly and at low cost has enabled the growth of the 3D printer market. To tailor products, the flow of materials as well as the assembly pathway are key considerations.