The big “DIP”per : The preparation of both l,l ‐DIP and l,d ‐DIP (see structures) involves a complex case of double asymmetric induction in the key step of the synthesis. The differential ability of each isomer to contribute to thermoprotection in the context of a key enzyme has been assessed and both isomers of DIP are shown to possess biological activity.
Substituted benzoxathiazines function as catalysts for the selective hydroxylation of tertiary C? H bonds. Mechanistic studies have revealed an unanticipated disparity between oxaziridine reactivity and catalyst performance and have given way to a new catalyst and an aqueous H2O2 reaction protocol that greatly facilitate such transformations (see scheme).
Metal‐free triazole turns : 1,5‐Disubstituted peptidyl triazoles are obtained regioselectively from the 1,3‐dipolar cycloaddition of peptidyl phosphoranes and azides. Peptide turns are thus formed that contain a conformationally locked cis peptide bond. Being regioselective and free of heavy metals, this reaction may find broad application in chemical biology and medicinal chemistry.
Pepped up polymers : The synthesis and properties of novel chiral cyclic peptides designed to complex with suitable polymers through hydrogen bonding are described. A substituted cyclic peptide self‐assembles into supramolecular nanotubes and develops noncovalent interactions with poly(vinyl alcohol) (PVA) by means of its carboxyl side chains.
Electrochemistry down to the molecular level was the main theme of the 59th annual meeting of the International Society of Electrochemistry (ISE, see logo). Around 1400 scientists from all over the world met in Seville to discuss modern aspects, progress in methods and new mechanistic insights.
A new way to make a bang : Several functionalized 1‐ethyl‐5‐aminotetrazoles, 1‐ethyl‐5‐nitrimino‐tetrazoles, and copper complexes have been synthesized and their chemical and energetic properties have been comprehensively characterized. The compounds belong to all classes of “energetic materials”: explosives, propellants, and pyrotechnics.
Finely tuned optical properties : The optical properties of substituted protected catechol derivatives can be fine‐tuned (see scheme; TBDMS=tert‐butyldimethylsilyloxy). The DFT‐calculated polarisabilities are compared with experimental data.
Contrasting magnetic properties : Two isostructural metal‐azido magnetic chains embedded in 3D threefold interpenetrated H‐bonded frameworks and separated by a long bpeado spacer have been assembled (see figure). Incorporation of Mn2+ displays a rarely observed antiferromagnetic Heisenberg chain, while incorporation of Co2+ displays a ferromagnetic Ising chain.
Dynamic transformation : A racemization catalyst and the enzyme Candida antarctica lipase B (CALB) were combined in a one‐pot dynamic kinetic resolution (DKR) of primary amines, which were transformed to their corresponding amides in up to 95 % yield and >99 % ee. This chemoenzymatic DKR was also applied to the synthesis of norsertraline (see scheme).
Light fantastic! Lu2O3:Yb3+/Er3+/Tm3+ nanocrystals with controllable red, green, blue (RGB) and bright white upconversion luminescence by a single laser excitation of 980 nm have been successfully synthesized (see picture). Due to abundant UC PL colors, it can potentially be used as fluorophores in the field of color displays, back light, UC lasers, photonics, and biomedicine.
