Research articles

The enantioselective construction of quaternary stereocentres, particularly those with all-carbon substituents, is a challenging problem in asymmetric synthesis. It has now been shown that an alternative retrosynthesis of aldol products provides an opportunity to form such stereocentres with a reaction that creates three new carbon–carbon bonds in a single step.

A survey of protein–ligand complexes shows that hydrogen bonds and halogen bonds that share a common oxygen-atom acceptor are often geometrically perpendicular to one another. Moreover, theoretical studies on small-molecule models of such systems predict that these two interactions are energetically independent.

Water can behave in unexpected ways at high pressure and temperature. Simulations of the detonation of a high explosive show that ‘extreme’ water can act as a chemical catalyst that promotes the transport of oxygen between reactive sites — contrary to the current view of water as a stable final product.

Molecules confined to small volumes can contort themselves into unusual conformations that differ from those usually observed when no constraints are placed on them. It is now shown that when normal alkanes are encapsulated inside self-assembled capsules, they adopt a coiled conformation and exert pressure inside their hosts.

Two closely related species of fungus each produce one enantiomer of the same natural product. The biomimetic synthesis of both enantiomers reported here supports the unusual conclusion that the two species have evolved to produce a pair of enantiomerically distinct enzymes.

The spectrally resolved fluorescence of a zinc–porphyrin dimer is used to quantify intracellular viscosity. The porphyrin dimer also acts as a singlet-oxygen sensitizer, and enables real-time observation of a surprisingly large increase in intracellular viscosity that occurs on singlet-oxygen-mediated photoinduced cell death.

Performing chemical reactions on ultra-small scales is important in a number of disciplines. Now, it has been shown that a junction formed by fusing two polymer nanowires preloaded with reactants provides an effective attolitre-volume in which reactions can be conducted on a zeptomole (10⁻²¹ mol) scale.

Adding low concentrations of aromatic organic cations to an aqueous solution in which polyoxometalate-based crystals are immersed leads to the spontaneous growth of tubular structures with controllable diameters. Tubes can be fused together to form junctions and are shown to act as channels through which liquids can flow.

Short nucleotides with just one or two bases do not generally form stable hydrogen-bonded pairs in water. Now, however, it has been shown that the hydrophobic interior of water-soluble coordination cages offers a sheltered environment in which stable duplexes can be formed.