Dorothée Laurenti

Palladium-tetraphosphine catalysed allylic substitution in water

Abstract The cis , cis , cis -1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3 H 5 )] 2 system catalyses allylic amination in water with very high substrate/catalyst ratio in good yields. A turnover number of 980 000 can be obtained for the addition of dipropylamine to allyl acetate in the presence of this catalyst.

Palladium–tetraphosphine catalysed cross coupling of aryl bromides with arylboronic acids: remarkable influence of the nature of the ligand

The cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane –[PdCl(C3H5)]2 system catalyses the cross coupling of aryl bromides with arylboronic acids with very high substrate–catalyst ratios in good yields; a turnover number of 28000000 can be obtained for the addition of 4-bromobenzophenone to benzeneboronic acid in the presence of this catalyst.

Dramatic acceleration of the catalytic process of the amination of allyl acetates in the presence of a tetraphosphine/palladium system

The cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)-cyclopentan e/[PdCl(C3H5)]2 system catalyses allylic amination in good yields with a very high substrate/catalyst ratio; a turnover number of 680 000 and a turnover frequency of 8125 h−1 can be obtained for the addition of dipropylamine to allyl acetate in the presence of this catalyst.

Hydroconversion of carboxylic acids using mesoporous SBA-15 supported NiMo sulfide catalysts under microwaves

Hydrogenation of octanoic acid was performed in a continuous manner, using microwaves (MW), and a supported metal sulfide catalyst. SBA-15, AlSBA-15 and ZrSBA-15 supported NiMo hydrotreating catalysts were prepared by an incipient wetness impregnation method in order to investigate the role of support acidity. Extrudates of the supported NiMo powders were prepared and sulfided. Octanoic acid in dodecane (10%) was introduced in the continuous flow reactor by means of an HPLC pump and co-fed with hydrogen at a working pressure of 0.5 MPa, while varying the reaction parameters such as temperature and feed flow rate (0.1, 0.25, and 0.5 mL min−1). The power applied to the monomodal cavity varied in the range of 15–150 W and corresponding temperature from 200–350 °C. Catalysts and supports were characterized by small- and wide-angle XRD, N2-physisorption (BET, BJH), HRTEM, ICP-MS, and NH3-TPD. The thermal response under MW showed that the extrudates containing SBA-15 (with or without Al or Zr) exhibited a strong MW response. The comparison of the catalytic activities showed that all SBA-15 supported NiMo catalysts exhibited the same activity range but the selectivity as compared to NiMo/Al2O3 catalysts was different.

Biosourced analogs of elastomer-containing bitumen through hydrothermal liquefaction of Spirulina sp. microalgae residues

The hydrothermal liquefaction of Spirulina sp. microalgae (i.e. cyanobacteria) byproducts was investigated for the production of road binders from renewable sources. In the 220–300 °C temperature range, a water-insoluble viscous material was obtained in a ca. 50% yield, which consisted of an oily fatty acid-based fraction mixed with organic and inorganic solid residues (ca. 20%). More interestingly, this material exhibited viscoelastic properties similar to elastomer-containing bitumen, when operating the hydrothermal liquefaction between 240 and 260 °C. This is the first example of a bio-sourced product showing such properties. At higher temperature, fragmentation of species of high molecular weight occurred, resulting in less viscous materials that were no more thermorheologically simple. The reactor filling ratio was also allowed to vary (i.e. 30% versus 60%), showing very little influence in terms of yield and viscoelastic properties of the resulting bio-binders.