?The biggest challenge facing scientists is finding a way to make clean energy. If I could have dinner with three famous scientists from history, they would be Marie Curie, Dmitri Mendeleev, and Henri Moissan. …?“ This and more about Véronique Gouverneur can be found on page 3559.
“My first experiment was preparation of proline‐derived chiral ligands for asymmetric alkylation. My favorite subjects at school were history and English…?.” This and more about Keisuke Suzuki can be found on page 2635.
Easy come, easy go? Transport resistances on particle surfaces are important for mass transfer in nanoporous materials and bulk diffusion in crystals. Interference microscopy and IR micro‐imaging are shown to be excellent tools for determining such transport resistances. By studying short‐chain‐length alkane guest molecules in crystals of the metal–organic framework compound Zn(tbip) a data collection of surface permeabilities is established.
Oxidizing gold? A gold(I)/gold(III) catalytic cycle is essential for the first oxidative cross‐coupling reaction in gold catalysis. By using Selectfluor for gold(I) oxidation, this chemistry reveals the synthetic potential of incorporating gold(I)/gold(III) catalytic cycles into contemporary gold chemistry and promises a new area of gold research by merging powerful gold catalysis and oxidative metal‐catalyzed cross‐coupling reactions.
Versatility : Ni0 and Pd0 complexes act as catalysts in the intramolecular aryl‐ and acylcyanation reactions, respectively, of alkenes (see scheme). These reactions not only proceed with high yield and selectivity, they also tolerate a wide range of functional groups and can furnish valuable heterocycles such as oxindoles, which are precursors for a myriad of natural and/or biologically active products.
Inorganic enzyme? Ceria nanoparticles exhibit unique oxidase‐like activity at acidic pH values. These redox catalysts can be used in immunoassays (ELISA) when modified with targeting ligands (see picture; light blue and yellow structures are nanoparticles with attached ligands). This modification allows both for binding and for detection by the catalytic oxidation of sensitive colorimetric dyes (e.g. TMB).
Recyclable organocatalysts : The first chiral DMAP analogue immobilized on magnetic nanoparticles is a highly active catalyst that is capable of the acylation of racemic sec‐alcohols under convenient, process‐scale friendly conditions (room temperature, 5 mol % loading, with acetic anhydride as the acylating agent) with excellent enantiodiscrimination. The catalyst is easily recovered and possesses unprecedented recyclability—in this study it was demonstrated to retain excellent activity and selectivity over 32 iterative cycles.
Alkynes of reactions : Recent breakthroughs in metal‐catalyzed alkyne reactions, which expand the synthetic utility of alkynes, have been achieved. These approaches broaden the range of alkynes that are accessible by C? N and C? C bond‐forming reactions and demonstrate that the use of bifunctional heterobimetallic catalysts can lead to new reactivity and excellent enantioselectivity (see scheme).
Indoles are not indolent : Various indoles react with arylboronic acids chemodivergently. C? H arylation of free indole and N‐methylindole gives the corresponding C(2)‐arylated indoles A whereas N‐acylated, N‐benzoylated, and N‐Boc‐protected indoles provide the corresponding arylcarboaminoxylated products B with excellent diastereoselectivity in good to excellent yields.
The appropriate choice of chiral catalyst and starting materials leads to the synthesis of 1,2‐oxazetidin‐3‐ones by cycloadditions of ketenes with nitroso compounds with very good regioselectivity and enantioselectivity. In addition to serving as potentially bioactive target molecules, the products can be transformed into other important classes of compounds, such as α‐hydroxycarboxylic acid derivatives.
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.
“My biggest motivation is to see my students′ progress. When I was eighteen I wanted to be unexcitingly, a chemist…︁!” This and more about Stefan Mecking can be found on page 3213.
Summary: We report a new method for the preparation of polyaniline nanoballs by using HAuCl4 as an oxidizing agent. During the reaction, aniline is oxidized and forms polyaniline whilst the hydrogen tetrachloroaurate is reduced and forms gold nanoparticles. These gold nanoparticles are found to decorate the nanoballs.
The resultant precipitate and corresponding TEM image of the gold‐nanoparticle covered polyaniline nanoball. 相似文献
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.
“My first experiment was the Wittig reaction to prepare chiral allenes. If I wasn′t a scientist, I would be a historian. …?” This and more about Yoshiaki Nishibayashi can be found on page 4276.
Catalytic convenience : The use of iridium or ruthenium catalysts for C? H bond activation has led to the addition reaction of trifluoromethylated compounds to alkenes (see scheme). This atom‐economical reaction occurs under neutral reaction conditions and without the formation of undesired defluorinated by‐products, even at high temperature.
Forces to reckon with : Supramolecular complexes, such as the one shown, are normally based on a combination of different interactions such as ion pairing, hydrogen bonds, and stacking interactions. The not always simple characterization of the nature and strength of intermolecular forces provides assistance to the understanding of biomimetic systems, as well as for the design of synthetic receptors, drugs, and intelligent materials.
