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The most important industrial process for the synthesis of vanillin is performed in two steps involving an electrophilic aromatic substitution of glyoxylic acid on guaiacol followed by an oxidative...

Homogeneous coating of carbon nanotubes with metallic nanoparticles was achieved using supramolecular auto-organization of amphiphilic molecules as template. The resulting Pd nanoparticles/carbon nanotube nanohybrids were then evaluated in electrocatalysis experiments, showing superior activity in ethanol oxidation compared to analogous systems.

A new and efficient procedure for ligand exchange on core−shell fluorescent nanocrystals is reported. The process involves the reaction of carbon disulfide with a ligand containing an amino group. The resulting dithiocarbamate is strongly bound to the surface of the quantum dots leading to a secure coating of the nanoparticle. The strategy was applied to the aqueous transfer of quantum dots.

We have described a spectacular salt effect in the kinetic resolution of (+/-)-1-phenylethylamine, which leads to an increase in reactivity, high levels of selectivity, and a complete reversal of the stereoselectivity. By tuning the reaction conditions, we were able to increase the selectivity factor of (1S,2S)-1 to s = 115.

The microscopic protonation mechanism, at an inframolecular level, of norbadione A, a pigment extracted from mushrooms and known to complex cesium cations, was determined by using 1H NMR titrations and the cluster expansion method. This study revealed a pH dependent Z to E isomer switch that occurs in both pulvinic moieties. As a consequence, norbadione A can exist in solution in four stereomeric forms (E−E, E−Z, Z−E, and Z−Z), which can be of interest in the development of molecular-level devices. In the presence of 0.15 M NaCl, the calculated microconstants showed an unusual apparent cooperativity between the enol groups, which results from the release of the sodium cations upon protonation of norbadione A.

Methallyltriphenylarsonium ylide polymerized in the presence of catalytic amounts of trialkylboranes. Linear polymers containing a terminal alcohol function were obtained after alkaline hydrogen peroxide oxidation. The chain of these polymers is constituted of methyl-substituted double bonds, separated by one methylene group. Their structure is related to that of natural rubber, in which the double bonds are separated by two methylene groups. These polymers arise from successive chain elongations of three carbon atoms at a time. A cyclic, polymeric ketone was also prepared from a cyclic trialkylborane. The mechanism, which involves a boratropic rearrangement after every insertion of a monomer, is discussed.

An original method to induce Diels-Alder cycloadditions on carbon nanotubes is reported. The process is based on the double activation of the nanotube surface by combining high pressure and Cr(CO)6. This allows the efficient functionalization of carbon nanotubes by electron-rich dienes.

(Z)-alpha-Fluoro-, (Z)-alpha-chloro-, and (Z)-alpha-bromoacrylates were obtained with unprecedented yield and stereocontrol (99%) via addition of the corresponding commercial trihaloacetates to aldehydes at room temperature using stoichiometric Cr(II) salts or catalytic Cr(II) with a regeneration system. The intermediate 2,2-dihalo-3-hydroxy adducts could be isolated in good yields under conditions of limited reagent at 0 degrees C.