Ennio Vanoli

Microwave barrel reactor use in trimethylolpropane oleate synthesis by Candida antarctica lipase in a biphasic non-solvent process

A novel microwave barrel reactor (MBR) was constructed and used in lipase catalyzed biolubricant synthesis. The MBR is thought as a versatile process tool for biotransformation and green chemistry that overcomes current size limitations in microwave reactors. A lipase mediated biotransformation in the MBR was compared to a state of the art jacketed reactor with external heat exchanger. Oleic acid and trimethylolpropane converted quantitatively (96%) into biolubricants using microwave induction. The heat dissipation in the MBR was analyzed by thermal imaging and inside thermometry. Conversion rates, rate constants and pseudo reaction orders were in line with conventional processing and no microwave effect was detected. The MBR is a versatile new reactor for non solvent, minimal and common solvent processing in the microwave field. While the subject of investigations was biolubricant synthesis in the MBR, the technology described is of wider potential interest in the field of biomass processing and sustainable chemical manufacture.

Influence of the hydrogen reduction time and temperature on the morphology evolution and hematite/magnetite conversion of spindle-type hematite nanoparticles.

We report on the transformation via hydrogen reduction of spindle-type hematite nanoparticles into hematite/magnetite hybrid iron oxide particles. The transformation process consists of the reduction of nanoparticles powder in an autoclave using hydrogen gas at a fixed pressure of 11 bars. Both temperature and time of reduction are varied between 300 °C to 360 °C and 0 to 45 h. X-Ray powder diffraction data on the obtained powder and corresponding Rietveld refinement allow the amount of reduced hematite to be determined as a function of these two parameters. Kinetics parameters are measured and an estimation of the activation energy is obtained through linearization of the Arrhenius equation. While reduction is dramatically accelerated at higher temperature, the morphology of the nanoparticles only remain qualitatively unchanged at 300 °C as seen from transmission electron microscopy images. The mechanisms underlying morphology changes are still under study and seem to be closely related to reactor pressure.

One-Pot Synthesis of Trifluoromethylated Quinazolin-4(3H)-ones with Trifluoroacetic Acid as CF3 Source

A novel and convenient one-pot sequential cascade method for the preparation of 2-trifluoromethylquinazolin-4(3 H)-ones is described. Trifluoroacetic acid (TFA) was employed as inexpensive and readily available CF3 source, which in the presence of T3P was condensed with a variety of anthranilic acids and amines to provide the products in up to 75% yield. The protocol was proved to be robust on 80 g scale, and the synthetic versatility of the prepared quinazolinon-4-ones was demonstrated by derivatization to further useful building blocks.

Exploration des liquides ioniques comme nouvelle classe de solvants pour les réactions chimiques

Ionic liquids based on laurylsulfates and tosylates anions were developed and characterized. A Heck reaction (synthesis of trans-ethylcinnamate) was optimized in 1-butyl-3-methyl-imidazolium-tosylate ionic liquid. The recycling of the reaction medium, including the catalyst and the ionic liquid, was carefully studied and the following results were obtained: eleven reactions were performed without further catalyst additions, the average yield was 85% with an average reaction time of 10 h.