Volume 5 Issue 1, 19 December 2014

N-heterocyclic carbenes are important catalysts for organic reactions. Here, the authors show that they can be used for asymmetric synthesis of carbon–carbon bonds through a non-covalent interaction mechanism, and apply this to a highly enantioselective Michael addition reaction.

MazF toxins inhibit bacterial growth by cleaving single-stranded RNA at specific sequences. Here, the authors describe a new genome-wide approach, MORE RNA-seq, for defining MazF cleavage specificity, and show that MazF-mt3 cleaves 23S and 16S ribosomal RNAs.

There is substantial research into hydrogen energy storage and transport. Here, the authors show that hydrogen can be stored in aqueous formaldehyde solution, with a hydrogen capacity potentially greater than for formic acid, and that the catalytic hydrogen release can be performed under relatively mild conditions.

Fundamental theories do not predict a difference between the properties of matter and antimatter, but experimental tests of this are still in their infancy. To this end, this study analyses the effects of electric fields on antihydrogen atoms in the ALPHA trap to place a bound on the charge of antihydrogen.

Some π-conjugated molecules exhibit tunable luminescence—a property that is useful for the next generation of optical devices. Yagai et al. propose a strategy to design these materials on a molecular level, which tailors the emission colour via structural changes in response to mechanical stimuli.

Changes in serum metabolites can indicate the development of disease. Here, the authors measure serum metabolite and lipoprotein levels in a large cohort of Northern Europeans, creating metabolic fingerprints for various age groups and, specifically, for women at the onset of menopause.

The benzene unit is a common scaffold in natural products and appears in most best selling drugs. Here, the authors report the efficient synthesis of substituted benzenes through a carbene-catalyzed formal [3+3] reaction, which does not require a pre-existing aromatic ring.

Long hydrocarbon chains are important biomolecules, but their selective recognition within synthetic hosts can be problematic due to the lack of specific binding sites. Here, the authors present a polyaromatic molecular tube capable of selectively binding a range of long hydrocarbons.

The regulatory role of calcitonin in bone homeostasis is well studied, yet its molecular activity is poorly understood. The authors show that calcitonin regulates bone cells function by inhibiting the osteoclast secretion of sphingosine 1-phosphate, a lipid mediator of osteoclast–osteoblast crosstalk.

In proton exchange membrane fuel cells, little is known about distribution of ionomers inside electrodes. Here, the authors present an electron tomography technique that allows a three dimensional visualization and quantitative analysis of ionomer layers in the electrodes.

The Achmatowicz reaction involves the conversion of furans into dihydropyrans, classically with the use of bromine. Here, the authors couple an enzymatic oxygen activation with a chloroperoxidase-mediated oxygen transfer, providing a biocatalytic route to a formal Achmatowicz reaction.

The highly strained nature of small bridgehead alkenes means that they often cannot be isolated, despite being postulated as transient intermediates. Here, the authors report base-stabilized heavy analogues of the smallest bridgehead alkene, with silicon occupying the vertices.

Strain-promoted cycloadditions are relatively slow and most work on increasing reactivity focuses on cycloalkyne structure. Here, the authors show a marked dependence upon the nature of the azide, which not only leads to increased rates but also enables orthogonality between coupling partners.

Direct alkylation of amines with alcohols is an atom-efficient and environmentally benign process. Here, the authors show that catalysts based on iron—an inexpensive and readily available metal—can carry out this process with high conversions and good substrate scope.

Copolymers are the combination of two or more different monomers, often alternating in defined patterns. Here, the authors show a gradient copolymerization of two monomers with different crystalline properties, giving polymers where the crystallinity varies throughout the length of the chain.

Various vertical surface emitting, terahertz quantum-cascade lasers have been proposed recently but these suffer from power cancellations in the far-field and limited extraction efficiencies. Here, Vitiello et al.circumvent these issues using two-dimensional photonic quasi-crystalline resonators.