Volume 8 Issue 3, March 2016

Vaccination with a synthetic glycoconjugate, in combination with the administration of an inhibitor that blocks capsular polysaccharide synthesis in bacteria, could offer an alternative route to combat bacterial infections.

Emulating the efficiency with which enzymes catalyse reactions has often been used as inspiration to develop self-assembled cages. Now two studies present approaches to achieving catalyst turnover — one of the biggest challenges in achieving truly biomimetic catalysis.

The use of renewable resources as providers to the electrical grid is hampered by the intermittent and irregular nature in which they generate energy. Electrical energy storage technology could provide a solution and now, by using an iterative design process, a promising anolyte for use in redox flow batteries has been developed.

While there is some qualitative understanding of how excess protons behave in acidic aqueous solutions, there is still much to learn about the structures they form with water molecules. Now, 2D infrared spectroscopy has enabled the definite identification of the 'Zundel cation' in protonated liquid water and an approximate determination of its lifetime.

In a remote functionalization, reaction occurs at a site distant from the site of initial activation. This Review discusses attempts to achieve this challenging goal with a particular focus on reactions that exploit alkene isomerizations to effect transit of the catalyst from a reactive alkene to a distant sp³ centre.

The Bergman cyclization is a fascinating rearrangement reaction with implications beyond organic chemistry. It has now been shown that a reversible Bergman cyclization reaction in a single molecule sitting on an ultrathin NaCl film can be triggered and directly imaged using atomic force microscopy. The interconverted diradical and diyne products are shown to have distinct chemical and physical properties.

Preorganization of catalysts and substrates can lead to significant rate enhancement—an effect often observed in enzyme catalysis. Now, a self-assembled nanosphere equipped with 24 guanidinium binding sites is demonstrated to strongly bind sulfonate-containing gold catalysts. Base-triggered co-encapsulation of carboxylate containing substrates leads to pronounced gating effects and dramatically enhanced reaction rates.

The Kemp elimination has been catalysed in the cavity of a coordination cage with a rate enhancement (k_cat/k_uncat) of 200,000 at pD 8.5. The catalysis requires two orthogonal interactions to bring together the components: hydrophobic binding of benzisoxazole, and accumulation of hydroxide ions at the cationic cage surface by ion-pairing.

Metal centres play an important role in the damage to biomolecules caused by radiation, but the respective microscopic mechanisms are unknown. Now it is shown that the absorption of X-rays by a metal ion leads to an intricate chain of ultrafast relaxation steps that results in the complete degradation of the metal's local environment.

The presence and linkage of unusual higher sugars in the ‘inner core’ of Gram-negative bacteria makes the core lipopolysacchride tetrasaccharide Hep₂Kdo₂ a tough target. Now, a 2+2 glycosylation strategy has facilitated the synthesis of this glycoconjugate. Synthesis of Hep₂Kdo₂ enabled an antibacterial vaccination strategy based on immunization with the glycoconjugate and the subsequent administration of an inhibitor that uncovers the corresponding epitope in pathogenic bacteria.

Interpenetration of metal–organic frameworks (MOFs) is a common phenomenon, in which a structure consists of two or more identical, entangled sub-lattices. Now, MOFs with variable, fractional degrees of occupancy of one of two sub-lattices have been prepared. The extent of interpenetration can be controlled either during synthesis or by autocatenation, a framework rearrangement process.

Until recently, the three-body recombination reaction was widely regarded as the only reaction pathway to the production of molecular oxygen in Earth's prebiotic primitive atmosphere. Observation of a CO₂ photodissociation pathway altered this view, but now, using anion velocity imaging, a further source of molecular oxygen is revealed, formed via the dissociative electron attachment to CO₂.

Self-replicating molecules provide a simple molecular level system to study the processes occurring in speciation. Now it is shown that in a pool of interconverting macrocycles, constructed from two building blocks, two distinct sets of self-replicating molecules emerge, and that one is a descendant of the other.

Highly compressible crystalline materials typically rely on the high compressibility of their chemical bonds. Now, a family of LnFe(CN)₆ frameworks (Ln = Ho, Lu or Y) has been shown to exhibit pronounced volumetric and linear compressibilities through a spring-and-gear mechanism instead, in which a torsionally flexible LnN₆ unit twists reversibly under pressure.

Enantioselective aldol reactions with fluoroacetate would enable access to numerous fluorinated analogues of therapeutically important compounds but have been a long-standing unsolved challenge. Now, bioinspired fluoromalonic acid half thioesters (F-MAHTs) have been devised and allow for highly stereoselective reactions with aldehydes under mild organocatalytic conditions.

Yuichiro Nagame ponders on the steps it took to make lawrencium, and its location in the periodic table.