Dramatic rate enhancement of reductive elimination of [Ar‐Pd‐C] was observed in the presence of a phosphine/electron‐deficient olefin ligand. Through systematic kinetic investigations of the Negishi coupling of ethyl 2‐iodobenzoate with alkylzinc chlorides (see scheme), the rate constants for reductive elimination of [Ar‐Pd‐C] were determined to be greater than 0.3 s?1, which is about four or five orders of magnitude greater than values reported previously.
Slip between the sheets! The intercalation properties of lamellar solid acids have a profound impact on nitrogen doping as well as on the resultant visible‐light photocatalysis, and the effects depend strongly on the protonic acidities of the samples (see figure).
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.
No templates needed : The title reaction makes it easy to construct the bicyclo[6.3.0]undecadienone framework in high yields (see scheme). A template effect is not required to achieve this ring‐closing reaction efficiently. The present method can be applied to the construction of bicyclo[5.3.0] and bicyclo[4.3.0] ring systems. Ts=p‐toluenesulfonyl.
Nanochannel alumina templates are used as templates for fabrication of porous gold nanowire arrays by a direct electrodeposition method. After modification with glucose oxidase, a porous gold nanowire‐array electrode is shown to be an excellent electrochemical biosensor for the detection of glucose. The picture shows an SEM image of a nanowire array after removal of the alumina template by acid dissolution.
A general solution : In situ synchrotron X‐ray scattering in a high‐pressure pulsed injection reactor (see picture) shows that magnetite nucleation and growth are temporally separated. Gram‐scale crystalline, pure phase, superparamagnetic magnetite nanoparticles were synthesized without surfactants in supercritical water in less than one hour using a laboratory‐scale continuous‐flow reactor.
A black whole : The black insoluble biopolymer eumelanin is prepared through the oxidative polymerization of 5,6‐dihydroxyindoles (see scheme). It has a largely unknown heterogeneous structure and unique optoelectronic properties. Current structural models are presented and possible applications are discussed.
Drugs turn the light off : Conjugated polyelectrolytes (CPEs) have been used in fluorescent assays for real‐time screening of small molecules that prevent the RNA–protein complexation that is important for virus replication and thereby can be considered potential initial candidates for drug discovery (see picture).
An efficient catalytic asymmetric Friedel–Crafts alkylation of indoles with alkylidene malonates has been developed by using a chiral N,N′‐dioxide–Sc(OTf)3 complex as the catalyst (see scheme). Some optically active intermediates containing the indole skeleton have been synthesized, such as indolepropionic acid, tryptamines, and β‐carbolines. The coordination between the scandium atom and the chiral N,N′‐dioxide compound has been revealed by X‐ray structure analysis.
Top down goes bottom up : A family of microporous interpenetrating diamond frameworks can be constructed from a pentanuclear tetrahedral complex with nitrate groups at the apical positions as an inorganic precursor. A “bottom‐up” methodology was used for substitution of the nitrate groups by linear ditopic carboxylate ligands (see picture). The Langmuir surface area of the resulting frameworks is higher than that of classical zeolites.
Two photons are better than one : This principle applies to a wide range of applications, ranging from engineering to physiology. Recent advances in our understanding of the phenomenon of two‐photon absorption (see picture) and in the design of two‐photon dyes are rapidly increasing the scope of this field.
