Meeting the demand for sugars : The importance of oligosaccharides and glycoconjugates in biological systems has stimulated a need to access significant amounts of these compounds. Much effort has been devoted to the stereoselective generation of the key glycosidic bond, both between carbohydrate residues (see scheme) and to the aglycone. Various methodologies are now available for the efficient synthesis of structurally defined complex oligosaccharides and glycoconjugates.
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).
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.
Surfing gold and silica! A new cholesterol‐based tether was attached to both amine‐functionalised silica and gold surfaces. The resultant self‐assembled monolayers, which can be deep‐UV‐patterned, were used in attaching essentially equivalent patterned supported lipid bilayers both on silica for fluorescence studies (left figure) and on gold for impedance studies (right figure).
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.
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.
Do the twist : The reaction of in situ generated phosphinidenes with phosphaalkynes is a facile route to the new metal‐coordinated η3‐diphosphavinylcarbene 1 , which shows facile ligand‐exchange reactions and undergoes an unprecedented rearrangement that involves phosphinidene complex 2 and η3‐phosphaalkenylphosphinidene complex 3 , the 1,3 isomer of 1 .
Alcohol oxidation and self‐assembly: the in situ oxidation of hydroxyl functional groups to quinone groups promotes the formation of enhanced hydrogen bonds and allows reorganization of the resulting supramolecular self‐assemblies, which evolve from a weakly bound dense phase to a strongly bound nanoporous open structure (see picture).
A remarkable twosome : Four‐coordinate square‐planar complexes based on [Zn(salen)] derivatives are conveniently captured inside a crystal matrix using a supramolecular protecting strategy (see figure). The four‐coordinate species is accompanied by a five‐coordinate complex that binds an axial ligand able to hydrogen bond to an N‐heterocycle positioned in the axial region of the coordinative unsaturated derivative. The size of the N‐heterocycle is a decisive stabilization parameter.
Reversible and non‐bonding interaction between SWNTs and ODCB is observed from the analyses of visible near‐infrared absorption data and Raman spectroscopies (see spectra). The solvent effect on SWNTs effectively controls the electronic structure of SWNTs under homogeneous conditions.
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.
Let's stick together : The gelation ability of a dendritic gelator has been enhanced by its complexation with a polyelectrolyte (see figure). This concept provides a route to construct novel functional or ordered materials by complexation of other low‐molecular‐mass functional species with polyelectrolytes.
Pd II ate complex : A novel alkylated pincer thioimido–Pd complex generated from a catalyst precursor and basic organometallic reagents (RM) was observed by in situ IR, 1H NMR, and 13C NMR spectroscopies for the first time and proved to be the active catalyst in stoichiometric and catalytic reactions of aryl iodides with RM (see scheme). The catalyst, as an electron‐rich PdII species, promoted the Negishi coupling of aryl iodides and alkylzinc reagents with high efficiency, even at low temperatures (0 or ?20 °C).
In a glass house : Silica‐encapsulated self‐assembled monolayers (SAMs) on tunable gold/silver nanoshells were used as labels for surface‐enhanced Raman scattering (SERS). This concept combines the spectroscopic advantages arising from maximum surface coverage and uniform molecular orientation of the Raman reporter molecules within the complete monolayer together with the high chemical and mechanical stability of the glass shell.
Bridge of Si's : Quantum‐chemical calculations suggest that the bonding situation in the recently synthesized “trisilaallene” is better described in terms of donor–acceptor interactions between two silylene ligands L and a naked silicon atom Si, which carries two lone‐pair orbitals, yielding the silylone SiL2. Further silylones SiL2 with different donor ligands Si have also been calculated, which might be possible to synthesize.
