On the big screen : A chiral biphenol catalyst screening protocol was developed for the rapid identification of enantioselective nucleophilic boronate reactions with acyl imines (see scheme). The approach successfully identified a unique catalyst for the reaction of aryl, vinyl, and alkynyl boronates. Mechanistic studies demonstrate boronate ligand exchange with the catalyst is necessary for activation towards nucleophilic addition.
Not blue but red‐brown : A [1]ferrocenophanium ion has been synthesized and isolated as a red‐brown crystalline salt, surprisingly different in color from characteristically blue‐green unstrained ferrocenium ions. Compared to the neutral iron(II) counterpart, the [1]ferrocenophanium ion displays a considerably higher ring tilt and an increased propensity for ring‐opening reactions.
Trapped! Mesopolymer‐entrapped Pt nanoparticles serve as an efficient catalyst for the hydrogenation of benzaldehydes in water at ambient temperature. In comparison with the commercial Pt/alumina catalyst, the Pt/FDU‐14 catalyst shows superior performance in the hydrogenation reaction. The catalyst afforded high turnover frequencies and was reusable more than nine times without loss of activity or selectivity.
Monodentate DNA binding of [PtCl(dien)]+ (dien=diethylenetriamine) complexes may considerably affect the biophysical properties of DNA and consequently downstream cellular processes as a result of a large increase in the bulkiness of the nonleaving ligand by multiple methylation (see illustration).
One step further in bio‐inspired catalytic epoxidation reactions was made in investigations on iron/imidazole catalyst systems (see the crystal of one example) with hydrogen peroxide as the terminal oxidant, in which it was shown for the first time that defined iron–imidazole complexes are capable of epoxidizing challenging aliphatic olefins. X‐ray studies, UV/Vis titrations, and NMR studies were carried out to clarify the mechanism.
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.
Size is not all! Investigation of the controlled release of tertiary alcohols from the surface of dendrimers and “stylomers” as polymer model systems (see scheme) showed that the polarity of the conjugates and structural modifications in close proximity to the release unit have a stronger influence on the rates of hydrolysis than the size (generation) or shape (linear or spherical) of the macromolecules.
Quick access : A concise and efficient formal synthesis of platencin has been accomplished in nine steps from a commercially available starting material. The synthesis utilized only one protecting group. The base‐catalyzed Michael cyclization of precursor 1 afforded the key diketone 2 , which was converted into the desired core structure 4 via the radical intermediate 3 .
Constructing α‐stereogenic amides and ketones : The highly regioselective and enantioselective conjugate addition of 1,3‐dicarbonyl compounds to 1,4‐dicarbonyl but‐2‐enes has been developed with the chiral bicyclic guanidine as catalyst (ee values up to 97 %; see scheme).
Bright lights : Fullerene–silica hybrid nanoparticles have bright photoluminescence, high photostability, and low cytotoxicity, which are assets for bioimaging agents. The origin of the photoluminescence of the nanoparticle is the C–O–Si bond (see picture).
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).
Turing lead into gold : Hollow hybrid PbSx–Au nanostructures of about 10 nm in diameter were synthesized using a one‐step reaction under mild experimental conditions. The redox reaction of gold precursors with PbS nanocrystals in the presence of dodecylamine leads to the hollow feature of hybrid nanostructures (see picture).
Block copolymers in seconds : Catalyst‐free, ambient‐temperature click conjugation of individual polymer strands becomes possible using novel ATRP‐derived cyclopentadienyl‐capped polymers in an extremely rapid hetero‐Diels–Alder cycloaddition with macromolecules equipped with electron‐deficient dithioester end groups prepared by the RAFT process.
