Preparation of chiral ruthenium(IV) complexes and applications in regio- and enantioselective allylation of phenols.

International audienceFacile preparations of chiral [Ru(Cp*)]- and [Ru(Cp')]-based allyl complexes featuring N,O chelate derived from (+)-nopinone are described. Single crystal X-ray structural analysis of one complex revealed the preferential configuration of the ruthenium centre and the orientation of the unsymmetrical allylic substituent. Applications of these complexes in catalysis for nucleophilic allylic substitution allowed regio- and enantioselective formation of branched allyl ethers from phenols

Application of bio-based solvents for biocatalysed synthesis of amides with Pseudomonas stutzeri lipase (PSL)

Bio-based solvents were investigated for the biocatalysed amidation reactions of various ester-amine combinations by Pseudomonas stutzeri lipase (PSL). Reactions were undertaken in a range of green and potentially bio-based solvents including terpinolene, p-cymene, limonene, 2-methyl THF, ɣ-valerolactone, propylene carbonate, dimethyl isosorbide, glycerol triacetate and water. Solvent screenings demonstrated the importance and potential of using non-polar bio-based solvents for favouring aminolysis over hydrolysis; whilst substrate screenings highlighted the unfavourable impact of reactants bearing bulky para- or 4-substituents. Renewable terpene-based solvents (terpinolene, p-cymene, D-limonene) were demonstrated to be suitable bio-based media for PSL amidation reactions. Such solvents could provide a greener and more sustainable alternative to traditional petrochemical derived non-polar solvents. Importantly, once the enzyme (either PSL or CALB) binds with a bulky para-substituted substrate, only small reagents are able to access the active site. This therefore limits the possibility for aminolysis to take place, thereby promoting the hydrolysis. This mechanism of binding supports the widely accepted 'Ping Pong - Bi Bi' mechanism used to describe enzyme kinetics. The work highlights the need to further investigate enzyme activity in relation to para- or 4-substituted substrates. A priority in PSL chemistry remains a methodology to tackle the competing hydrolysis reaction

Palladium catalysed carbonylation of terminal alkenes to alpha,beta-unsaturated esters & Allylic C-H functionalisation of unsaturated hydrazine carboxylates to vinyl isoxasolidines

In the first part of the thesis, the aim was to devise a new simple catalytic system based on palladium to allow insertion of carbon monoxide in the presence of an alcohol into unsaturated systems with retention of the double bond to give an unsaturated ester. The process is known as oxidative carbonylation. To allow the process to become catalytic, the palladium needs to be reoxidised in situ. Optimal conditions for the catalytic system were developed and a wide range of substrates have been examined. Simple terminal alkenes and alkenes bearing functional group have been successfully carbonylated (yield 16%-87%). The method was applied to the synthesis of a known pharmaceutical intermediate. The aim of the second part was to develop an efficient system for the intramolecular oxidative amination of unsaturated hydrazine carboxylates to form novel vinyl oxazolidines. After optimisation of the reaction conditions, the scope and limitations of the reaction were established. Attempts were also carried out to develop an enantioselective version of the cyclisation. The method was applied to the synthesis of a known intermediate in a sequence towards (-)-kainic acid thus accomplishing a formal total synthesis of this compound

Palladium-catalyzed alkoxycarbonylation of terminal alkenes to produce α,β-unsaturated esters: the key role of acetonitrile as a ligand

A mild protocol has been developed for the Pd-catalyzed alkoxycarbonylation of terminal olefins to produce α,β-unsaturated esters with a wide range of substrates. Key features are the use of MeCN as solvent (and/or ligand) to control the reactivity of the intermediate Pd complexes and the combination of CO with O, which facilitates the Cu-mediated reoxidation of the Pd complex to Pd and prevents double carbonylation. Acetonitrile is the key! A mild protocol has been developed for the Pd-catalyzed alkoxycarbonylation of terminal olefins to produce α,β-unsaturated esters with a wide range of substrates (see scheme). Key features are the use of MeCN as a solvent (and/or ligand) to control the reactivity of the intermediate Pd complexes and the combination of CO with O, which facilitates the Cu-mediated reoxidation of Pd to Pd and prevents double carbonylation

Oxidative Azo–Ene Cyclization

An expedient procedure for catalytic oxidative azo–ene cyclization of allylic and homoallylic 1,2-hydrazinedicarboxylates is reported. The reaction produced a wide range of cyclic carbamate derivatives featuring an appended alkene fragment ready for further functionalization

Recommandations méthodologiques pour le montage de projets collaboratifs entre auteurs de la Recherche et des Territoires.

L’objectif de ce travail est de faciliter le montage de projets collaboratifs entre acteurs de la recherche (i), usagers des sols (ii) et acteurs publics ou privés des territoires (iii) pour une meilleure prise en compte des sols dans les territoires.Ce document s’adresse à deux types de lecteurs : les experts de la recherche et des territoires susceptibles de s’impliquer dans l’élaboration de projets partenariaux sur un ou plusieurs enjeux (facilitateurs, porteurs et acteurs de projets) et les financeurs potentiels de tels appels à projets, avec parfois des rubriques spécifiques aux uns ou aux autres.Le groupe a également réalisé un poster en anglais sur ce travail