Total Synthesis of (−)‐ and (+)‐Decarbamoyloxysaxitoxin and (+)‐Saxitoxin

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.

     

An Efficient Strategy to Drive Nanoparticles into Carbon Nanotubes and the Remarkable Effect of Confinement on Their Catalytic Performance

Are you in? Bimetallic PtRu nanoparticles have been selectively confined inside or deposited outside carbon nanotubes (see picture). The confined nanoparticles display significantly higher selectivity and catalytic activity in hydrogenation reactions.

     

Synthesis,Structure, and Application of Self‐Assembled Copper(II) Aqua Complex by H‐Bonding for Acceleration of the Nitroaldol Reaction on Water

Simple addition : Copper(II) aqua complex 1 can be prepared in a one‐pot synthesis and is self‐assembled by H‐bond interactions. Complex 1 is shown to accelerate the nitroaldol reaction on water, which is a heterogeneous process, requiring no additive or base, and 1 can be recycled without loss of activity.

     

Structural and Electronic Properties of Ultrathin Tin–Phthalocyanine Films on Ag(111) at the Single‐Molecule Level

Heads or tails? The evolution of structural and electronic properties of tin–phthalocyanine films has been analyzed for sub‐monolayer to multilayer coverage using low‐temperature scanning tunneling microscopy. Two molecular conformations are observed: randomly dispersed for the first layer, and islands with a single conformation in subsequent layers.

     

Iron‐Mediated Cleavage of C?C Bonds in Vicinal Tricarbonyl Compounds in Water

Three of a kind : Vicinal tricarbonyl compounds undergo C? C cleavage mediated by ferric ions (see scheme). The observed cleavage of ninhydrin and dehydroascorbic acid has relevance for amino acid detection and the metabolism of vitamin C.

     

Asymmetric Hydroboration of 1,1‐Disubstituted Alkenes

A breakthrough in the asymmetric hydroboration of notoriously difficult 1,1‐disubstituted alkenes using a new family of highly effective hydroboration reagents is described (see scheme). The intermediate boranes can be oxidized to alcohols or used in Suzuki–Miyaura cross‐coupling reactions.

     

Formation and Reactivity of Phosphorus–Selenium Rings

Lawesson reagent for selenium fans : Phosphorus selenium heterocycles and, in particular, [PhPSe₂]₂ (known as Woollins' reagent) are proving valuable in the synthesis of new heterocycles and for the insertion of selenium into organic substrates. Incorporation of phosphorus and selenium atoms into the products leads to a surprising variety of structures.

     

Fast Synthesis of Benzofluorenes by Selenium‐Mediated Carbocyclizations

When one ring is not enough : A new double cyclization of stilbene derivatives results in benzo[b]fluorenes via dihydronaphthalenes. The presence of a selenium electrophile and a Lewis acid are crucial for the formation of the C? C bonds.

     

Structure and Reactivity of a Unique Y‐Shaped Tricoordinate Bis(silyl)platinum(II)–NHC Complex

Y not? A unique, three‐coordinate Y‐shaped bis(silyl)platinum(II) complex was isolated and characterized (see structure; C light gray, N blue, Si pink, Pt dark gray). DFT studies on a model system shed light on the nature of this unusual coordination mode for platinum(II).

     

A Ditopic Ion‐Pair Receptor Based on Stacked Nucleobase Quartets

Pass the salt, please! State‐of‐the‐art computations indicate that the stacking complex of a guanine quartet and an adenine quartet (G₄A₄) can function as a potent ditopic receptor for NaCl in aqueous solution (see picture; Na⁺, Cl^? yellow, O red, N blue, C black, H white).

     

Efficient Synthesis of the Deoxysugar Part of Versipelostatin by Direct and Stereoselective Glycosylation and Revision of the Structure of the Trisaccharide Unit

Sweets for my sweet ! Efficient synthesis of the deoxysugar part of versipelostatin (VST) was achieved by direct and stereoselective glycosidation of the reduced VST aglycon. Comparison of the synthetic and natural VST products using NMR indicate that VST has a β‐d‐digitoxose‐(1,4)‐α‐l‐oleandrose‐(1,4)‐β‐d‐digitoxose trisaccharide. A biological assay indicates that the deoxyoligosaccharide unit of the synthetic glycoside is important for biological activity.

     

Total Synthesis of Ciguatoxin

Eines der Haupttoxine bei Fischvergiftungen, das Ciguatoxin (siehe Struktur), war Ziel einer Totalsynthese. Der Syntheseweg beruht auf der Kupplung dreier Segmente, und die Schlüsselumwandlungen umfassen eine Komplexbildung zwischen Acetylen und Dicobalthexacarbonyl.

     

Sonochemical Synthesis of Highly Luminescent Zinc Oxide Nanoparticles Doped with Magnesium(II)

Mut zur Lücke : Mg/ZnO‐Nanopartikel mit heller, stabiler Photolumineszenz in kolloidalen Dispersionen wie im Festkörper bilden sich durch Dotierung von Mg²⁺‐Ionen in ZnO‐Nanopartikel durch sonochemische Synthese. Ihre Bandlücken und Lumineszenzeigenschaften verändern sich mit der Defektkonzentration in den ZnO‐Nanopartikeln. Diese Konzentration hängt vom molaren Mg/Zn‐Verhältnis ab (siehe Bild).

     

Conventional and microwave irradiation assisted synthesis of new 1,2,4‐triazepine‐3‐thiones

New 1,2,4‐triazepine‐3‐thiones have been obtained during the respective reactions of N‐substituted‐hydrazino carbothioamides with dimethyl acetylenedicarboxylate and dibenzoyl acetylene under prolonged reflux in acetic acid and/or DMF. However, the reaction of the starting materials in DMF under microwave irradiation afforded the same products in higher yields within a few minutes.     

A Retrospective on the Design and Synthesis of Novel Molecules through a Strategic Consideration of Metathesis and Suzuki–Miyaura Cross‐Coupling

Synergy in synthesis : Strategic consideration of metathesis and Suzuki–Miyaura (SM) cross‐coupling for C? C bond‐formation processes has opened up new and “green” synthetic routes to various complex targets. The use of this synergistic combination for the synthesis of supramolecular ligands, polyaromatic compounds, and complex natural products is covered in this Focus Review.