Analysis of Dibenzyltoluene Mixtures: From Fast Analysis to In-Depth Characterization of the Compounds.

The so-called dibenzyltoluene (H0-DBT) heat transfer oil contains numerous isomers of dibenzyltoluene as well as (benzyl)benzyltoluene (methyl group on the central vs. the side aromatic ring). As it is used as a liquid organic hydrogen carrier (LOHC), a detailed analysis of its composition is crucial in assessing the kinetic rate of hydrogenation for each constituent and studying the mechanism of H0-DBT hydrogenation.

The reaction of organic peroxy radicals with unsaturated compounds controlled by a non-epoxide pathway under atmospheric conditions.

Today, the reactions of gas-phase organic peroxy radicals (RO) with unsaturated Volatile Organic Compounds (VOC) are expected to be negligible at room temperature and ignored in atmospheric chemistry. This assumption is based on combustion studies ( ≥ 360 K), which were the only experimental data available for these reactions until recently. These studies also reported epoxide formation as the only reaction channel.

Reactions of organic peroxy radicals, RO, with substituted and biogenic alkenes at room temperature: unsuspected sinks for some RO in the atmosphere?

Until now the reactions of organic peroxy radicals (RO) with alkenes in the gas phase have been essentially studied at high temperature ( ≥ 360 K) and in the context of combustion processes, while considered negligible in the Earth's atmosphere. In this work, the reactions of methyl-, 1-pentyl- and acetylperoxy radicals (CHO, CHO, and CHC(O)O, respectively) with 2-methyl-2-butene, 2,3-dimethyl-2-butene and for the first time the atmospherically relevant isoprene, α-pinene, and limonene were studied at room temperature (298 ± 5 K). Monitoring directly the radicals with chemical ionization mass spectrometry led to rate coefficients larger than expected from previous combustion studies but following similar trends in terms of alkenes, with (in molecule cm s) = 10 to 10 × 2/2 and = 10 to 10 × 5/5.

Solvent-free, metal-free, aza-Prins cyclization: unprecedented access to δ-sultams.

Aza-Prins and the pauper: Aza-Prins cyclization between γ,δ-unsaturated tosylamines and aldehydes was successfully performed under solvent-free and metal-free conditions. When applied to β,γ-unsaturated sulfonamides, the corresponding δ-sultams were isolated in good yields (see scheme). This approach constitutes a new route to cyclic sulfonamides.

Hexafluoroisopropanol: a powerful solvent for the hydrogenation of indole derivatives. Selective access to tetrahydroindoles or cis-fused octahydroindoles.

Pd/C in HFIP was used to hydrogenate indole derivatives under relatively mild conditions, leading to potential synthetic intermediates of bioactive compounds. Depending on their substitution, tetrahydroindoles or octahydroindoles could selectively be obtained.

Green chemistry: solvent- and metal-free Prins cyclization. Application to sequential reactions.

Prins cyclization between a homoallylic alcohol and an aldehyde, promoted by trimethylsilyl halide, afforded 4-halo-tetrahydropyrans with good to excellent yields. Thanks to the absence of the solvent and metal, the THP thus obtained have been implicated without purification in several other reactions, in a sequential way, affording in particular new indole derivatives.

One single catalyst, Pd(OAc)2, for two sequential very different steps: allylic alcohol oxidation-Heck reaction. Access to functionalised alpha,beta-unsaturated ketones.

A single addition of the catalyst, Pd(OAc)(2), was realised to mediate two transformations as different as allylic alcohol oxidation under O(2) and C-C bond formation of the Heck type, to give substituted alpha,beta-unsaturated ketones without intermediate purification.

Rapid cleavage of unactivated, unstrained amide bonds at neutral pH.

Building upon the discovery of Suggs and Pires that N-(2-hydroxyethyl)glycine amides undergo rapid amide cleavage under mild conditions [ Suggs, J. W. ; Pires, R.

Designer amphiphiles based on para-acyl-calix[8]arenes.

The synthesis of a series of fully O-derivatised para-acyl-calix[8]arenes is described, where the acyl function is either octanoyl or hexadecanoyl. The groups attached at the phenolic face are, carboxymethoxy (anionic), carboxypropoxy (anionic), 4-sulfonatobutoxy (anionic), ethoxycarboxymethoxy (neutral), ethoxycarboxypropoxy (neutral), 2-methoxyethoxy (neutral) and 2-(2-methoxy)diethoxy (neutral). The use of specific synthetic routes has allowed complete substitution in high yields for all the compounds obtained.