Articles in 2019

An automated platform that can synthesize a wide range of complex glycans could greatly facilitate progress in glycoscience. Now, a fully automated process for enzyme-mediated oligosaccharide synthesis has been developed. This process uses glycosyltransferase-catalysed reactions performed in solution, with product purification being accomplished by solid phase extraction using a sulfonate tag.

Amphiphilic self-assembly is ubiquitous both in nature and synthetic systems, yet the underlying mechanisms governing the transition from molecules to assemblies have not yet been fully resolved. Now, the role of liquid–liquid phase separation prior to the assembly process has been explored through the detailed analysis of a model block-copolymer system.

A concise strategy for engineering functional, supramolecular protein complexes has now been developed based on single-mutation-mediated covalent tethering. Metalloproteins designed with this method can sustain large alterations to the metal coordination environment, bind small molecules, exhibit reversible redox activity and sustain large alterations to the protein structure.

Single-molecule force spectroscopy reveals that maleimide–thiol adducts can be stabilized by stretching through a force-dependent kinetic control mechanism. This unconventional use of mechanochemistry enabled us to produce stable polymer–protein conjugates by simply applying a mechanical force to the maleimide–thiol adducts through mild ultrasonication.

Heterometallic clusters have shown promise in catalysis and small-molecule activation, but species comprising uranium–metal bonds have remained difficult to synthesize. Now, facile reactions between uranium and nickel precursors have led to nickel-bridged diuranium clusters supported by a heptadentate N₄P₃ scaffold. Computational analysis points to an unusual electronic configuration for uranium, U(iii)-5f²6d¹.

Conjugated mesopolymers can combine the advantages of polymers and oligomers, but have received less attention as semiconducting materials. Now, such compounds have been synthesized by direct arylation polycondensation that exhibit high molecular regularity, solubility and solution processability. These mesopolymers also show electron mobilities that are significantly better than those of their polymer counterparts.

Lanthanum is the first lanthanide — or the last. Or it’s not a lanthanide at all. In any case, Brett Thornton and Shawn Burdette are sure that it’s an element that might or might not be in group three of the periodic table.

Michelle Francl suggests that we should expand our view of the periodic table to new dimensions.

Most compounds form crystals so small that scientists cannot experimentally determine their atomic structures using X-ray crystallography. Microcrystal electron diffraction now provides a unique solution for this challenge.

Intersystem crossing plays a role in the mechanism of many reactive collisions between atomic species and organic molecules, and has been generally observed when the reactants are still approaching one another. Now, intersystem crossing has been observed to also occur after their initial interaction.

Strained boronate complexes have now been shown to enable an unprecedented cross-coupling reaction across a C–C σ-bond. Using this approach, highly functionalized cyclobutanes can be prepared with excellent stereocontrol from readily available reagents.

The elements of the periodic table are more integral to our daily lives now than they have ever been before. Bruce C. Gibb takes a look at the factors used to decide just how critical the supply of any given mineral is.

A two-coordinate monovalent gold complex that features a highly polarized aluminium–gold covalent bond, Al^δ+–Au^δ−, has been synthesized using a very strongly electron-donating aluminyl ligand. In solution, the complex reacts as a nucleophilic source of gold towards heteroallenes such as carbodiimides and CO₂.

Developing a stable metallic lithium anode is necessary for next-generation batteries; however, lithium is prone to corrosion, a process that must be better understood if practical devices are to be created. A Kirkendall-type mechanism of lithium corrosion has now been observed. The corrosion is fast and is governed by a galvanic process.

One-dimensional diffusive binding represents an important mechanism used by nature to facilitate many fundamental biochemical processes. Now, a completely synthetic system with similar capabilities has been constructed. The system was exploited to significantly speed up bimolecular reactions and to catalytically transport molecular cargo in solution and within physically separated compartments.

Anchored single-atom catalysts have recently been shown to be very active for various processes, however, a catalyst that features two adjacent copper atoms—which we call an atom-pair catalyst—is now reported. The Cu₁⁰–Cu₁^x+ pair structures work together to carry out the critical bimolecular step in CO₂ reduction.

Despite their huge potential in medicinal chemistry, current approaches for the synthesis of fluorinated piperidines are often impractical. A straightforward process for the rhodium-catalysed dearomatization–hydrogenation of fluoropyridines has now been described. This strategy enables the highly diastereoselective formation of a variety of all-cis-(multi)fluorinated piperidines and the study of their conformational behaviour.

Symmetrical protein oligomers perform key structural and catalytic functions in nature, but engineering such oligomers synthetically is challenging. Now, oppositely supercharged synthetic variants of normally monomeric proteins have been shown to assemble via specific, introduced electrostatic contacts into symmetrical, highly well-defined oligomers.