Three attractions in one cage : Various magnetic networks are formed in the three polymorphs of an organic magnet, BBTDA(=benzo[1,2‐d:4,5‐d′]bis[1,3,2]dithiazole)?GaBr4. The three phases show quite different magnetic behaviors in spite of having the same chemical formula. Their magnetic differences originate from the relative configuration of the neighboring organic radical molecules in their crystals.
“ Quat's” the story? N‐Aryl amides are effective directing/activating groups for chlorosilane Lewis acids. This aspect has been exploited for the development of the first simple and general method for the highly enantioselective Pictet–Spengler reaction of ketimines derived from α‐ketoamides leading to quaternary α‐amino acid derivatives (see scheme).
Throw your hat in the ring : A highly diastereoselective synthesis of the ABC rings of (?)‐norzoanthamine has been achieved starting from the (?)‐Hajos–Parrish ketone (see scheme). Three asymmetric quaternary carbon centers on the C ring were constructed by a 1,4‐addition, and an intramolecular Diels–Alder reaction provided a trans‐decalin scaffold on the AB rings.
Total synthesis through block glycosylation and selective chemical O‐sulfation of tyrosine residues yielded the glycopeptide recognition domain A (X=SO3?) of the P‐selectin glycoprotein ligand 1, in which the terminal sialic acid of the complex hexasaccharide side chain was replaced by (S)‐cyclohexyl lactic acid. In binding assays the O‐sulfated structure A showed high affinity towards P‐selectin, the non‐sulfated towards E‐selectin.
Organic π‐conjugated polymers have emerged as one of the most fascinating classes of materials as they have found utility in a host of plastic electronics technologies. The distance between π‐systems and their relative orientation dictate energy/charge transfer, conductivity, and photophysical properties of these materials in bulk. This Feature Article discusses π‐conjugated polymers and model compounds in which specific inter‐π‐system interactions are covalently enforced and the effect that the scaffolding has on optoelectronic properties.
Playing the sax : The enantioselective total syntheses of (?)‐ and (+)‐decarbamoyloxysaxitoxin (doSTX) and (+)‐saxitoxin (STX) are reported. A new methodology was developed for the synthesis of STXs, featuring discriminative reduction of the nitro group and N? O bond in nitroisoxazolidine.
Preferred protonation : Does electrospray ionization mass spectrometry produce gas‐phase or liquid‐phase structures? The preferred protonation site in p‐aminobenzoic acid depends upon the medium, and the structure of its conjugate acid varies with the solvent used during spraying.
Intelligent design : The total synthesis of the cytotoxic (?)‐FR182877 relies on 1) tandem Diels–Alder reactions to close rings A–D (see scheme), 2) a palladium‐mediated 7‐exo‐trig reaction, and 3) an iridium‐mediated isomerization followed by epimerization and stereoselective reduction.
Amorphization tunes acidity : Pseudo‐bridging silanols, suggested as versatile Brønsted acid groups by molecular modeling studies, are obtained by shifted hydrolysis of Si? O? Al bridges formed by the thermal treatment of silica deposited on γ‐Al2O3 (100), and appear under given pretreatment conditions. Demixing of part of the silica from the aluminosilicate phase is predicted upon excess water adsorption.
Taking shortcuts : A remarkably short and high‐yielding asymmetric total synthesis of (?)‐oseltamivir takes advantage of organocatalysis and single‐pot domino operations. The target, known as the drug Tamiflu, is prepared efficiently in a short time, and also its derivatives can be synthesized effectively.
Weaving an intricate web : A stereoselective synthesis of (?)‐agelastatin A has been developed, which requires 11 steps from commercially available starting material. The application of a Rh‐catalyzed intramolecular olefin aziridination reaction and the subsequent manipulation of the resulting tricyclic intermediate (see scheme) punctuate this study.
Don′t be square! A rare S42? rectangle bridging two M2Cp2(μ2‐CH2)2 (M=Rh, Ir) fragments is found to contain two “half‐bonds” with S? S distances of 2.70 or 2.90 Å. Computational studies explore the connection between these “half‐bonds” and a Jahn–Teller distortion, as well as possible intermediates that form M4S42+ clusters having the S42? rectangle rotated by 90°.
A mimic for nature's solar cells : Simple mixing of nonaporphyrin macrocycle N‐( 1 –Zn)3 and acceptor ligand C60–ZnP–Tripod affords a supramolecular architecture (see scheme), in which the excitation energy collected by the macrocycle is transferred efficiently to the central ZnP acceptor, inducing charge separation between the ZnP and C60 sites.
