The missing link : Ferrocene and porphyrin monolayers are tethered on silicon surfaces with short (see picture, left) or long (right) linkers. Electron transfer to the silicon substrate is faster for monolayers with a short linker.
Easy and direct : Regioselective Mizoroki–Heck‐coupling reactions using heteroaromatic tosylates as electrophiles were achieved, thus providing direct and easy access to highly functionalized α‐heteroarylvinyl amides and ethers.
A simple but effective copper‐catalyzed borylation of aryl halides, including electron‐rich and sterically hindered aryl bromides, with alkoxy diboron reagents occurs under mild conditions (see scheme). Preliminary DFT studies of the mechanism suggest that σ‐bond metathesis between a copper–boryl intermediate and the aryl halide generates the aryl boronate product.
Doing the hula twist? A photochemically stimulated inversion of an sp2‐hybridized oxygen atom upon simultaneous rotation of two adjacent bonds may be possible in a pure singlet excited potential energy surface in uninhibited fluid media (see scheme).
The shortest He–He distance! r(He–He)=1.265 Å. The electronic interaction between confined pairs of He atoms in the C20H20 dodecahedrane cage is analyzed (see figure). A key observation about bonding that emerges uniquely from endohedral complexes is that a short internuclear separation does not necessarily imply the existence of a chemical bond.
Two members of a family of pyrrole–imidazole marine alkaloids, (+)‐dibromophakellin and the nonnatural congener (+)‐phakellin, were synthesized enantioselectively from 4‐hydroxy‐L ‐proline. The chiral aminal at C10 was constructed efficiently by means of an Overman‐type [3,3] sigmatropic rearrangement of an enamide (see scheme).
Cutting carbons : The three‐dimensional structure of polyneuridine aldehyde esterase (PNAE) gives insight into the enzymatic mechanism of the biosynthesis of C9‐ from C10‐monoterpenoid indole alkaloids (see scheme). PNAE is a very substrate‐specific serine esterase. It harbors the catalytic triad S87‐D216‐H244, and is a new member of the α/β‐fold hydrolase superfamily. Its novel function leads to the diversification of alkaloid structures.
Fullerene flakes : A diacetylene‐functionalized fullerene derivative self‐organizes into flakelike microparticles (see picture). Both the diacetylene and C60 moieties can be effectively cross‐linked, which leads to supramolecular materials with remarkable resistivity to solvent, heat, and mechanical stress. Moreover, the surface of the cross‐linked flakelike objects is highly durable and water‐repellent.
Which form to take? The interconversion between the G‐quadruplex and duplex DNA forms in the bcl‐2 promoter could be induced by fluctuations in the pH value or DNA and NH4+ concentrations, by adding CH3OH, and by introducing small molecules (cationic porphyrin and dehydrocorydaline; see scheme).
Form and function : The natural product myxopyronin A provides the key to understanding the inhibition of bacterial RNA polymerase and should spark new ideas for the design of new antibiotics against tuberculosis and other infectious diseases.
Traffic control : By exploiting the interplay of kinetic and thermodynamic effects, the direction of threading/dethreading in a nonsymmetric calixarene wheel can be selected by an appropriate choice of the head group incorporated in the molecular axle (see figure).
Just a drop of water : Esterification in water is possible by confining the reactants in small miniemulsion droplets protected by nonionic surfactants. A lipase located at the interface between the droplet and aqueous surroundings catalyzes the esterification and expels generated water from the reaction site (see picture). High yields of the ester can be obtained after short reaction times under ambient conditions.
