Just subtract water : Amphiphilic π‐conjugated acyclic oligopyrroles form solvent‐assisted H‐aggregates that give rise to vesicular structures in aqueous solution (see figure). The H‐aggregates are sensitive to the conditions and are transformed into J‐aggregates by the removal of water.
Let it flow, let it flow : A procedure to generate the first solid‐supported mercuric salt, silaphenylmercuric triflate, is described. Silaphenylmercuric triflate showed remarkable catalytic activity for an indole synthesis, furanoyne cyclization, arylyne cyclization, and tandem carbocyclizations. An efficient flow reaction system for indole synthesis and arylyne cyclization is also described (see figure).
With a sting in its tail : An enantiopure neodymium complex (see scheme) acts as an efficient single‐site initiator for the controlled ring‐opening polymerization of rac‐lactide, forming isotactic polyester. The heteroscorpionate complex was characterized spectroscopically and by X‐ray diffraction.
To each his own : An addressable electrochemical device consisting of orthogonally arranged rows and columns of electrodes has been constructed to monitor protein expression in genetically engineered cells at the single‐cell level. The response based on redox cycling reflected the different expression levels of the enzyme from individual HeLa cells transfected with a plasmid vector including secreted alkaline phosphatase.
First insights into the reaction between a Baylis–Hillman adduct and an allene moiety have been obtained from the novel domino heterocyclization/cross‐coupling reaction of α‐allenols and Baylis–Hillman acetates, which furnishes [(2,5‐dihydrofuran‐3‐yl)methyl]acrylate derivatives in moderate to good yields.
A growing attachment : Porous coordination polymer (PCP) nanorods are synthesized by modulation of the coordination equilibria between framework components, which regulates the rate of framework extension and crystal growth. Investigation of the crystal growth mechanism by TEM indicates that face‐selective modulation on the surfaces of PCP crystals enhances the anisotropic crystal growth of nanorods by an oriented attachment mechanism.
Suprapolymers : The synthesis of symmetrically end‐functionalized polymers in a single step has been developed by means of ring‐opening metathesis polymerization by using a bimetallic ruthenium initiator and functional chain terminators. Self‐assembly of the resulting polymers allows for the formation of supramolecular alternating block copolymers (see figure).
N‐Heterocyclic carbenes do it again! [Pd(SIPr)(PCy3)] ( 1 ; SIPr=N,N′‐(bis(2,6‐diisopropylphenyl)imidazolidine), which is stable under H2, was shown to be a highly active catalyst for the hydrogenation of a wide range of alkenes and alkynes. Reactions proceed under mild conditions (relatively low Pd loading, RT, low pressures of H2) even when sterically hindered alkenes (tri‐ and tetra‐substituted) are used.
Molecular architecture affects the properties of surface layers. Photosensitive silanes with branched architectures allow patterning and coupling of proteins and cells on surfaces while maintaining their biofunctional state. Attachment can be directed to the activated regions of irradiated substrates with high selectivity (see image of mouse fibroblasts).
A new family in town! Treatment of a rare‐earth metal (Ln) and either a potential divalent rare‐earth metal (Ln′) or an alkaline earth metal (Ae) with 2,6‐diphenylphenol (HOdpp) at elevated temperatures (200–250 °C) afforded heterobimetallic aryloxo complexes (see figure). Both a charge‐separated species, [(Ln′/Ae)2(Odpp)3][Ln(Odpp)4], and a neutral species, [AeEu(Odpp)4], were obtained and crystallographically characterised.
Diaminations are a girl's best friend : New reactions in the field of transition‐metal‐catalyzed diamination of olefins provide a powerful tool for the elaboration of more complex molecules bearing the 1,2‐diamine moiety. An overview of these methods, including asymmetric versions, is given.
In control : A new catalytic vinylogous Mukaiyama aldol reaction provides products with high diastereo‐ and enantioselectivities (up to 99 % de and ee; see scheme). The relative and absolute stereochemistry of a representative product was rigorously assigned by NMR and CD spectroscopies (measured and calculated), X‐ray diffraction, and quantum‐chemical calculations.
All change : Complete ligand exchange through the hydrogenation of [Ru(η4‐cod)(η6‐cot)] in the presence of GaCp* under mild conditions leads to the title complex featuring a “naked” gallium atom bridging two ruthenium centers (see structure: C white, Ga blue, Ru red). This cluster can be considered as a trapped intermediate on the way to mixed‐metal nanoparticles; cot=1,3,5‐cyclooctatriene; cod=1,5‐cyclooctadiene, Cp*=C5Me5.
Synergistic interactions between N and F can be used to tune the band structures of N‐doped TiO2 (see scheme). Reduction potential of conduction band electron is positively shifted to weaken unwanted O2 reduction, but enhances the target reduction reaction in air. The tuning also enhances the oxidation ability of the valence band to oxidize water to O2, which makes photocatalytic reduction proceed without any organic sacrificial reagents.
Size matters! The electronic structure and size‐dependent stability of neutral and cationic scandium‐doped copper clusters have been investigated by mass spectrometric studies (for the cations) and also quantum chemical computations. The proposed reaction paths ultimately lead to the most stable Frank–Kasper‐shaped Cu16Sc+ cluster (shown here), which could be the germ of a new crystallization process.
Secondary, but second to none : The use of secondary alkyl halides in transition‐metal‐catalyzed cross‐coupling reactions (see scheme) has advanced significantly over the last five years. Selected examples of these transformations are examined, including mechanistic and stereochemical aspects.
Confined, but happy : The triflate salt of a germanium(II) dication, an atomic cation of a nonmetal, was isolated by encapsulation in [2.2.2]cryptand (see formula and molecular structure in the crystal). The cryptand satisfies the electron demand of the cation and sterically protects it (see space‐filling depiction, right).
