No longer left to the imagination: Nonplanar amides have intrigued chemists for decades. This year, a story 60 years in the making came to an end: 2-quinuclidone has finally been synthesized and isolated in the form of its HBF₄ salt (see scheme).

. ‥ and to cap it off: Capillary NMR (CapNMR) spectroscopy is emerging as a major breakthrough in increasing the mass-sensitivity of NMR spectroscopic analysis. As discussed in the Minireview, not only is the acquisition of the spectra of mass-limited samples getting easier but the quality of CapNMR spectra obtained in many small-molecule applications exceeds what can be accomplished with conventional probe designs.

Well-orchestrated sequences of events: The virtues of cascade reactions are the focus of this Review, which discusses a number of recent total syntheses that feature these processes, highlights developments in the field, and points to its promising future.

Images of the masses: Two-dimensional molecular imaging of intact rat brain tissue under ambient conditions was achieved by using the mass spectrometric technique of desorption electrospray ionization (DESI). The distributions of specific lipids, such as sulfatide 24:1, reveal distinctive subanatomical features of the rat brain (cc=corpus callosum; aca=anterior part of anterior commissure) with spatial resolution of less than 500 μm.

Room to expand: A rare example of thermal spin crossover in a Mn^III complex is accompanied by elongation of the bonds to the equatorial N₄ donor set upon warming (see scheme; Mn purple, N blue, O red), which is consistent with population of the d orbital. The spin crossover was observed for an N₄(O⁻)₂ donor set with axial oxygen donors, whereas only a temperature-independent high-spin state was observed with these donors in a cis arrangement.

Thin end of the wedge: A block molecule, which consists of a rigid wedge-shaped aromatic segment linked at its apex to a flexible poly(ethylene oxide) chain, self-assembles into cylindrical nanofibers in both polar and nonpolar solvents. The structure of the nanofibers changes reversibly in response to solvent polarity, from highly flexible coil-like cylinders in water to stiff rodlike aggregates in n-hexane (see picture).

Knocking them into shape: The total synthesis of two reported marine natural products containing halogenated pyrano[3,2-b]pyrans (see example in blue) has led to the reassignment of both structures as halogenated 2,2′-bifuranyls (red). Concomitantly an efficient route to pyrano[3,2-b]pyrans is described.

Seeing red: Highly sensitive and selective chemical sensing systems were developed for the naked-eye detection of toxic ions by the direct and indirect postgrafting of hydrophilic and hydrophobic chromophores into spherically nanosized cavities of cubic Fm3m monoliths (HOM-C10). This leads to reliable control over the visual detection of toxic metals such as Pb^II, Cd^II, Sb^III, and Hg^II ions at a low concentrations (≈10⁻⁹ M). DZ= diphenylthiocarbazone.

Right to the core: A ruthenium(I) complex of corannulene, prepared in a solvent-free environment, exhibits two coordination modes of the bowl: η²-rim and η¹-hub (see picture for the hub-coordinated complex; Ru purple, O red, C gray, H white). The latter represents the first example of a transition-metal center binding only to the fullerene-like interior of an open geodesic polyarene.

It's all in the mix: A mixed-surfactant-templated synthesis gives noncrystalline metal–boron nanotubes (see picture: TEM image of Fe–B nanotubes; inset: the corresponding selected-area electron diffraction pattern) from simple starting materials under mild conditions. These nanotubes show better catalytic activity for the hydrogenation of m-nitrotoluene to m-toluidine than the corresponding nanoparticles.

Chutes and …︁ Ladders in coordination networks represent a boundary between 1D and 2D systems. Halogen-bridged Pt^II/Pt^IV mixed-valence ladder compounds have been synthesized for the first time. In these compounds, the band gap is controlled by changing the bridging halide ions. Moreover, by changing counteranions, the charge arrangements of the ladder compounds can be controlled.

Several carbon–carbon bond-forming reactions are catalyzed by a silica-supported scandium triflate catalyst combined with an ionic liquid. The combination of these two components creates a hydrophobic reaction environment in water (see scheme; blue: water, yellow: substrate, orange: ionic liquid).

Lots of writing on the wall: A simple and flexible approach for performing high-throughput, large-area, direct-write molecular patterning, without tip feedback, is demonstrated by using a 55 000-pen two-dimensional array of atomic force microscope (AFM) cantilevers. The use of low-aspect-ratio pyramidal tips, curved cantilevers, and a novel gravity-driven alignment method allows parallel patterning of molecules across 1-cm² substrate areas at sub-100-nm resolution.

Rewriting the end: Two unmodified oligodeoxyribonucleotides (ODNs) were photochemically ligated through modification of ODNs that contain photosensitive nucleosides at both terminal ends in the presence of a template ODN. Additionally, this method was applied to the synthesis of R-shaped DNA as a unique structure.

Controlling guests: Porous coordination polymers containing mobile organic groups, such as naphthalene rings (see picture), are synthesized, and their rotational motion is characterized by solid-state ²H NMR spectroscopy. The rotation of the groups can be switched off (blue) by guest (blue spheres) adsorption and switched on (yellow) again by guest desorption.

Very selective but very easy: These are two of the attributes of the asymmetric vinylogous Mannich reactions presented herein. These reactions can be run on a gram scale and in undistilled THF and air (see scheme; TMS=SiMe₃). All that is needed is commercially available AgOAc, a readily available amino acid derived phosphine, and a commercially available or easily prepared (one step) siloxyfuran.

Uranyl interactions: The title compound is the first example of an actinide compound that contains three different actinyl-ion coordination geometries, namely, octahedral, pentagonal bipyramidal, and hexagonal bipyramidal. Strong cation–cation interactions between the uranyl ions lead to pentamers with a rather unusual configuration (see picture; U dark gray, O light gray).

Multicomponent method: Tubulysins are among the most potent cytotoxic agents known. Now the first total synthesis of some members has been achieved by utilizing a rapid three-component reaction for the synthesis of the unusual central thiazole amino acid tubuvaline (see scheme; Boc=tert-butoxycarbonyl, Ac=acetyl), thereby opening new perspectives for anticancer drug development.

Biomineral-forming organisms provide inspiration for developing new reaction pathways to functional materials, such as rutile for optical devices. A recombinant protein (rSilC) was designed based on the sequence of a silica-forming protein from a diatom. This unique protein induced the formation of hierarchically nanostructured rutile microcrystals under mild reaction conditions (see SEM image).

An open and closed case: Estradiol was conjugated to a PAMAM dendrimer (gray circle) through a short (17α-phenylethynyl) or a long (hexaethyleneglycol) tether to evaluate how ligand access to a receptor is affected. With the short tether (a), the hormone is free and solvent exposed, with unimpeded access to the estrogen receptor, while the long tether (b) wraps around the hormone and the dendrimer and markedly reduces access to the receptor.

No rings of fire! Enantiopure primary phosphanes have been developed which are remarkably stable to air oxidation in both solid and solution states (see example). This new class of stable ligand synthon appears to owe its stability to conjugation in their aryl backbones with the extended π ring system. Even one extra ring is good enough.

Steaming ahead: The nonvolatility of ionic liquids is challenged further. Imidazolium(Im)-based ionic liquids composed of supramolecular structures in the condensed phase (see scheme) vaporize at ambient pressure from heated (100–600 °C) solvent droplets as neutral clusters of the type Im_nA_n.

An active link: A diglycine-containing linker (cat⋅linker) was fabricated on Rink amide resin for dual functions: a) attachment of a scaffold and b) capture of metal ions for promoting on-resin reactions (see picture). The metal-catching feature of the linker proves essential for the solid-phase synthesis of indoles through microwave-assisted Cu^II-mediated heteroannulation.

A tetrahydropyran intermediate, prepared from (−)-diethyl tartrate, was used to assemble the C31–C67 fragment of amphidinol 3. Both of the tetrahydropyran rings in the natural product were prepared from this intermediate. The polyene segment was assembled with high selectivity.

An additional azidomethyl group dramatically decreases the melting points of the corresponding azidopyrimidines. Theoretical calculations show that these polyazido compounds (see picture; N light blue, C dark blue, H white) exhibit highly promising energetic properties. 2,4,6-Triazidopyrimidine was found to be a novel precursor to carbon nanotubes in the presence of Ni(ClO₄)₂.

Elusive intermediate trapped: γ-Substituted difluoropropargyl groups can stabilize an organoindium(III) complex. The resulting structure is the only known example of an indium atom bonded to a propargylic carbon atom (see picture; F blue, S yellow, C white, H green). Reactions with electrophiles produced a difluoroalkyne or -allene, depending on the type of electrophile.

Taming of the wild anions: Highly labile naphthalene complexes of formally negative-valent later transition metals have been obtained in the form of [Co(η⁴-C₁₀H₈)(η⁴-cod)]⁻ (see picture; cod=1,5-cyclooctadiene) and [Co(η⁴-C₁₀H₈)₂]⁻. The latter is the first structurally authenticated homoleptic bis(naphthalene)metal anion for any d-block element and promises to be a particularly reactive synthon for the “naked” atomic cobalt anion.

New kid on the block: Unprecedented polystyrene-block-poly(methylenephosphine) copolymers are accessible from the reaction of living polystyrene with the phosphaalkene (see scheme; Mes=2,4,6-Me₃C₆H₂). The living anionic polymerization of PC bonds represents a new development in phosphorus chemistry and opens up the possibility to synthesize functional phosphorus polymers of controlled architectures.

Sidestepping a cyclic side product: Copolymerization of terminal epoxides with CO₂ was investigated by using a cobalt(III) complex bearing a piperidinium end-capping arm and a piperidinyl arm (see scheme; DME=1,2-dimethoxyethane). The catalyst system can selectively produce copolymers without contaminant formation of cyclic carbonates even at high conversion of the epoxide (>99 %).

Preferential growth of MgO(111) nanosheets with a thickness typically between 3 and 5 nm (see TEM image) has been achieved by a simple, efficient, and inexpensive wet chemical route. The MgO(111) nanosheets have been shown to have ultrahigh activity for the Claisen–Schmidt condensation of benzaldehyde and acetophenone.

Go with the flow: In many applications of NMR spectroscopy in chemistry, proper sample preparation is absolutely critical for success, in particular in biochemical and biomedical areas. For the NMR spectroscopy of laser-polarized ¹²⁹Xe, an efficient and robust method for continuous flow of the gas to a NMR tube was developed. Applications to H₂O, DMSO, phospholipid bicelles, and 2D exchange NMR spectroscopy are demonstrated.

The tin salt Sn(NTf₂)₄ (Tf=trifluoromethanesulfonyl) is an efficient catalyst for the selective and ring-size-specific cycloisomerization of highly substituted 1,6-dienes to give six-membered-ring carbocycles (see scheme; X=C(CO₂Et)₂, C(CO₂Me)₂ C(CN)(CO₂Et), etc.). This is the first Lewis acid catalyzed cycloisomerization of this type of substrate.

An elegant method for the aqueous-phase hydroformylation of 1-octene with a water-soluble Rh catalyst and amphiphilic latex particles as phase-transfer agents has been developed (see scheme). In this way, substantial concentrations of the olefin in the aqueous catalyst-containing phase were reached, and thus reasonable turnover frequencies under mild reaction conditions could be achieved.

Inequivalent in the crystal: The three chemically distinct calculated proton shielding tensors of solid benzene—a consequence of interactions in the crystal—can be described as the superposition of the isolated molecule and the intermolecular shielding contributions. In the ovaloid representations of the shielding tensors 1, 2, and 3 indicate the least, intermediate, and most shielded principal axes, respectively.

Building bridges: The wheels of [3]rotaxane were intramolecularly tethered to yield the first member of cyclochiral, interlocked architectures named “bonnanes” (after the city Bonn, Germany; see scheme). The enantiomers and meso form were separated on an immobilized chiral phase and characterized.