Retained : An N‐heterocyclic carbene with eight cyclohexyl groups (see figure) provides increased electron density for a highly active olefin metathesis catalyst as well as sufficient steric bulk to allow the efficient separation of such a complex from the organic products in the solvent‐resistant nanofiltration.
Simple and brilliant : 1‐Substituted 1H‐indole‐2‐carboxylic acids efficiently undergo successive diarylation accompanied by C? H bond cleavage and decarboxylation upon treatment with aryl bromides in the presence of a palladium catalyst system to afford fluorescent 2,3‐diarylindoles. This facile synthetic method provides a highly efficient blue emitter with a quantum yield of 0.97 in the solid state (see scheme).
Novel thin‐film materials have been produced from indolo[3,2,1‐jk]carbazole (see picture). These are conducting and redox‐active and, unusually, consist of three distinct covalently coupled luminescent dimer species, consistent with a specific radical‐cation coupling mechanism.
Available in small print : Block copolymer lithography has great potential for reducing the size and fabrication time of integrated circuits. Hydrogen‐bonding‐mediated molecular recognition in self‐assembly processes can be used to produce highly ordered square arrays of block copolymers on the surface of a silicon substrate (see picture).
Pressing the configurational switch : Use of enantiomeric Ir catalysts allows the vinylpiperidine building blocks 2 a and 2 b to be synthesized with high selectivity. Total syntheses of the dendrobate alkaloid (+)‐241 D, its C6‐epimer, and a spruce alkaloid are presented as applications.
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.
Biomimetic tandem protein/lipid damage : The reactions of reductive reactive species, produced by γ irradiation of water, with Zn and Cd complexes of a metallothionein from a plant afford diffusible sulfur‐centred radicals generated from methionine residues and sulfide ligands. These species migrate from the aqueous phase to the lipid bilayer and transform the cis double bond of the oleate moiety to trans isomer (see scheme).
Click–click cyclopeptides : Well‐defined biomolecular assemblies are synthesized using orthogonal oxime bond formation and copper(I)‐mediated alkyne–azide cycloaddition reactions in a stepwise or in a one‐pot approach. To illustrate this strategy, regioselective ligation of biologically relevant peptides onto a cyclopeptidic scaffold was performed.
Changing places : Intramolecular B(pin)/H exchange took place in the presence of a platinum–phosphane catalyst, giving synthetically useful cis‐β‐methyl‐substituted alkenylboronates stereoselectively (see scheme; B(pin)=4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl).
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).
Silica scaffolding : By employing functionalized mesoporous SBA‐15 silica, novel fluorescent cruciform‐silica hybrid materials are generated which preserve the desirable solution properties of cruciforms in the solid state for potential use in sensory schemes.
An addition to the family : The introduction of β‐amino acid residues into a modified amyloid β peptide fragment resulted in well‐defined helical nanoribbons (see cryo‐TEM image) comprising β strands mainly oriented perpendicular to the ribbon axis. The nanoribbons order into a flow‐aligning nematic phase at higher concentration. The β‐strand nanoribbon structure is an addition to the known set of secondary structures adopted by β‐peptides.
Healing hands : A complex interplay between colloidal and polymeric energetics in microgel self‐assembly behavior results in soft colloidal assemblies with self‐healing properties. Repulsive soft spheres can adopt highly compressed conformations in colloidal crystalline lattices without directly contacting the nearest neighbors (see picture). This distant action is directly responsible for the self‐healing of the assemblies.
Clicking in zeolites : Copper(I)‐exchanged zeolites proved to be practical and efficient catalysts for the cycloaddition of azomethine imines with alkynes, providing a convenient access to N,N‐bicyclic pyrazolidinone derivatives (see scheme). With high regioselectivity, 100 % atom economy, and convenient product isolation, this heterogeneously catalyzed version of the Dorn cycloaddition corresponds to click‐chemistry criteria.
Panacea for aldol desymmetrizations : We describe an easy entry for the desymmetrization of 4‐substituted‐cyclohexanones catalyzed by proline, using as cocatalysts different hydrogen‐bonding donors (see scheme), which dramatically improves the catalytic efficiency of proline in desymmetrization reactions.
