Shine a light with cyanates : A novel approach for the synthesis of urea complexes and homoleptic cyanates of alkaline earth metals and europium is described. The compounds have been fully characterized, including their magnetism and temperature‐dependent luminescence properties (see graphic).
Making ends meet : The L ‐gulopyranosyl trichloroacetimidate and 1,6‐anhydro‐2,3‐di‐O‐benzyl‐β‐L ‐gulopyranose, efficiently derived from L ‐ascorbic acid, were individually used as a starting unit and an elongation unit to prepare L ‐guluronic acid linked alginate oligosaccharides in excellent α selectivity and in good yields.
Carbonylation gets a phase lift : The usual liquid‐phase, high‐pressure processes for carbonylating formaldehydes are avoided in a novel vapor‐phase reaction. Using an acid zeolite (Faujasite) at near‐atmospheric pressure dimethoxymethane (DMM; the dimethyl acetal of formaldehyde; see scheme) is carbonylated to produce methyl methoxyacetate (MMAc). This approach provides a new route to ethylene glycol under mild conditions.
Alpha, beta, gamma! Amino substituents in alpha and beta positions allow the isolation of free carbenes, but even in the gamma position, their strong π‐electron‐donating properties permit the synthesis of allenylidene lithium adducts and silver complexes (see picture), which are ideal precursors for the preparation of various transition‐metal–allenylidene complexes.
When the truth stands on one leg : Arsenate coordinates at the water–goethite interface in a predominately monodentate fashion (see picture), a finding that impacts oxoanion bioavailability and challenges theories of mineral dissolution and surface complexation.
Radical assembly : Halogen bonding has been observed for the first time between an isoindoline nitroxide and an iodoperfluorocarbon (see figure), which cocrystallize to form a discrete 2:1 supramolecular compound in which N? O.???I halogen bonding is the dominant intermolecular interaction. This illustrates the potential use of halogen bonding and isoindoline nitroxide tectons for the assembly of organic spin systems.
Responsive supramolecular gels were constructed from crown ether terminated four‐arm star poly(ε‐caprolactone) (PCL–DB24C8) and dibenzylammonium‐terminated two‐arm PCL–DBAS (see scheme), exploiting the formation of pseudorotaxane linkages between crown ether and ammonium moieties. The resultant supramolecular gels exhibit thermo‐ and pH‐induced reversible gel–sol transition.
Double protection : Efficient Fmoc‐based solid‐phase synthesis (SPPS) of sulfotyrosine (sY) peptides is achieved by incorporating the sY residue(s) as a dichlorovinyl‐protected (DCV) sulfodiester(s) and using 2‐methylpiperidine for Fmoc removal. After removal of the other protecting groups, the DCV group could be cleaved by mild hydrogenolysis giving the sY peptides in good yield.
Enlightening the memory : The integration of a crosslinkable photochromic dithienylperfluorocyclopentene (DTE) into organic light‐emitting diodes (OLED) allows for the individualization of the emissive area of the OLED device, for example, for signage applications. The operation principle is based on switching the injection barrier for holes (positive charge carriers). Very large ON/OFF ratios of up to 3000 for current as well as electroluminescence have been achieved.
Extreme makeover of cholesterol : Cholesterol exchange is a major reason for the instability of liposomes in blood. The formation of a covalent hybrid between cholesterol and glycerophosphocholine preserves the bilayer‐stabilizing effect of free cholesterol but prevents its transfer from the bilayer. Thus, disterolphospholipids (e.g. 1 ) are valuable new components for liposome formulation.
