pHLIP opens the door to the cell: An improved cytosolic transfer of anti-microRNAs (anti-miRs) against onco-miRs paves the way for future cancer therapies. The employed anti-miR–peptide conjugates are based on peptide nucleic acids (PNAs), which are connected with the membrane translocation peptide pHLIP through a disulfide bond. The PNAs are thus transferred into the cell and released by the cleavage of the SS bond (see scheme).

There′s nothing like gold: New gold(III) catalysts, which can be easily obtained by the oxidative addition of biphenylene to NHC-gold(I) chlorides (see structure; NHC=N-heterocyclic carbene) prove not only to be very stable compounds but also competent catalysts for various reactions. Some of these reactions are new, and have never been observed before.

1+1=3: By combining the exceptional reactivities of cyclic hypervalent iodine reagents and iron catalysts, Sharma and Hartwig achieved the azidation of CH bonds with unprecedented efficiency and selectivity. The late-stage introduction of azides into complex bioactive molecules will greatly facilitate the synthesis of analogues and accelerate the discovery of new chemical entities.

The analogy goes further: Following the often-studied donor–acceptor-substituted cyclopropanes, the corresponding cyclobutane derivatives were employed for the ring-strain-driven stereoselective syntheses of carbo- and heterocycles.

Dual role for catalysts: Novel routes for the generation of asymmetric stereocenters using photoredox catalysis were recently developed. Different chiral catalytic systems allowed new CC bonds to form in good yields and enantioselectivities using a mild methodology in which light is used as the energy source.

Confusion leads to cooperative reactivity: Oxidative ring-closure reactions of oligopyrranes containing two terminal confused pyrroles yield expanded porphyrinoids, which show cooperative reactivity between the directly linked confused pyrroles. These transformations constitute a new method for the synthesis of novel porphyrinoids with unconventional pyrrole linking modes and unique properties.

It cuts both ways: The CRISPR/Cas9 genome engineering system has been extended from DNA to RNA. The sequence-specific targeting and cleavage of RNA can be achieved with S. pyogenes Cas9–gRNA if an appropriate short single-stranded oligonucleotide, the “PAMmer”, is added. This technique could lead to a general approach for sequence-specific RNA manipulation.

Powering up 2D materials: Recent experimental studies confirmed the existence of piezoelectricity—the conversion of mechanical stress into electricity—in two-dimensional single-layer MoS₂ nanosheets. The results represent a milestone towards embedding low-dimensional materials into future disruptive technologies.

The magical HAT: Radical hydrofunctionalization processes of alkenes recently witnessed tremendous progress. The coupling of heteroatom-substituted alkenes was achieved by means of catalytic hydrogen atom transfer (HAT), enabling the construction of functionalized quaternary centers with unusual ease. Challenging thermodynamically controlled hydrogenations and isomerizations of alkenes as well as reductions of vinyl halides were accomplished using HAT processes.

Learning from classics: Crystal growth is a complex process, and there are multiple paths for going from dissolved ions to solid crystals. Highlighted herein is the application of traditional chemistry concepts to new ways for increasing the complexity of nanocrystals while maintaining a high degree of symmetry.

The recently discovered non-heme oxidase UndA catalyzes the conversion of lauric acid into 1-undecene. For the discovery, an impressive number of 6000 bacterial clones bearing a genome library of Pseudomonas fluorescens had to be screened by gas chromatography. The discovery of UndA is a breakthrough, as it paves the way towards the biotechnological production of medium-chain 1-alkenes from renewable materials.

Rarer than a new element: Recently Wang et al. produced the [(Ir^+IX)O₄]⁺ ion by a pulsed laser vaporization/thermal expansion method and studied it by IR photodissociation spectroscopy. The oxidation state of +IX had been unknown previously. The picture shows the mass spectra for the argon-tagged iridium oxide species.

The presence of a Lewis acid, typically a borane, in the coordination sphere of transition metals (Ni, Fe, Pt) offers a new way to activate H₂ and strong HE (E=Si, C) bonds.

Significant gains in energy savings now underway can be traced to a single invention—the blue light-emitting diode. GaN-based blue LED technology not only resulted in efficient white light sources, but continues to enable a host of applications and scientific inquiries. The researchers primarily responsible for the development of the blue LED were awarded the 2014 Nobel Prize in Physics.

Organocatalytic click! Recent advances in the metal-free enamine/enolate-mediated azide–carbonyl [3+2] cycloaddition reaction are discussed. These approaches require neither a metal catalyst nor alkyne substrates. Owing to the ready availability of carbonyl compounds, these methods thus offer excellent alternatives for the synthesis of 1,4-/1,5-disubstituted and 1,4,5-trisubstituted 1,2,3-triazoles.

High-turnover catalysis offers a novel concept for the efficient chemo- and enantioselective preparation of chroman intermediates, which are useful for the synthesis of tocopherols (vitamin E components) and other biologically active compounds. A chiral ammonium iodide catalyst mediates the cycloetherification in combination with a cooxidant and an inorganic base in excellent yield and up to 93 % ee. OTs=para-toluenesulfonyl.

The split up: Recent advances in photochemical dinitrogen splitting have been achieved. Demonstration of the reversibility of the N₂ splitting and ammonia formation from a nitride has advanced the field of N₂ fixation using a synthetic homogeneous system.

A big honor for small objects: The Nobel Prize in Chemistry 2014 was jointly awarded to Eric Betzig, Stefan Hell, and William E. Moerner “for the development of super-resolved fluorescence microscopy”. This Highlight describes how the field of super-resolution microscopy developed from the first detection of a single molecule in 1989 to the sophisticated techniques of today.

From first principles: In recent studies the lattice energy of crystalline benzene was predicted with sub-kilojoule per mole accuracy. Fundamental to this success was the combination of a fragment approach with state-of-the-art electronic structure methods.

Thiyl radicals at play: Thiyls are significant free-radical intermediates both in biology and chemistry. The recent search for new enantioselective methods in radical chemistry has led to the inclusion of these radicals in the toolbox of chiral organocatalysts.