Thèses soutenues

Doctorat sous la direction des Drs Yann Sarazin & Jean-François Carpentier à Institut des Sciences Chimiques de Rennes (ISCR), UMR 6226 CNRS.

Titre : Alkaline-earth and zinc homogeneous catalysis for the dehydrocoupling of hydrosilanes with terminal alkynes.
Date : 14 janvier 2026.
Composition du jury : Yann Sarazin et Jean-François Carpentier (co-directeurs de thèse, ISCR Rennes), rapporteurs externes Jean-Claude Berthet (CEA Saclay) et Armelle Ouali (ICGM Montpellier).

Résumé :
Dehydrocoupling (DHC) between hydrosilane and a terminal alkyne is a reaction where the Si–H bond of the hydrosilane reacts with the C–H (sp) bond of the terminal alkyne, to form a Si–C(sp) bond. During this process, dihydrogen (H2) is released as a by-product. This thesis decribes our efforts in substrate-catalyst optimisation and mechanistic studies towards the selective formation of molecular alkynylsilanes and macromolecular poly(alkynylsilane)s using group 2 and 12 metal-based catalysts. We found that, among different alkaline-earth catalysts, Ba{N(SiMe3)2}2(thf)2 is the most active one; pyridine, used as solvent, proved to play an instrumental role. However, Zn(OTf)2–pyridine turned out to be a more stable and selective catalyst system, especially for difunctional silanes. This system allowed us to prepare well-defined oligo(alkynylsilanes), and we evidenced how the choice of difunctional monomer affects the selectivity of the reaction. Early photophysical tests showed the produced oligomers have tunable UV–Vis absorption properties. Overall, the work provides practical ways to carry out these DHC reactions and insights for designing functional silane-based materials.

Liste des publications associées :
Barium-catalysed dehydrocoupling of terminal alkynes and hydrosilanes, ChemistryEurope 2026, 4, e202500401, DOI: 10.1002/ceur.202500401.
Iron(II) catalyzed activation of Si–N and Si–O bonds using hydroboranes. Organometallics 2023, 42, 3013-3024. DOI: 10.1021/acs.organomet.3c00339 Hal Id: hal-04261558
Lithium fluoroarylsilylamides and their structural features. Main Group Met. Chem. 2023, 20230012. DOI: 10.1515/mgmc-2023-0012   HAL Id: hal-04149132

Doctorat sous la direction des Drs Mathieu Pucheault et Laurent Chabaud à Institut des Sciences Moléculaires (ISM) Univiversité de Bordeaux.

Titre : Carbenes-borane et halogénures d’aryle : de la chimie radicalaire photo-induite à l’étude de boroniums.

Date : 16 novembre 2026.
Composition du jury : Mathieu Pucheault, Laurent Chabaud, Amandine Guérinot, Gaëlle Chouraqui, Sami Lakhdar, Sébastien Bontemps.

Résumé :
This manuscript deals with photo-induced reactions between a NHC-borane and aryl halides. Firstly, a light-induced dehalogenation of aryl iodides with carbene-borane was developed. Dehalogenated products bearing a large diversity of functional groups were obtained with high yields. When a deuterated NHC-borane was used, bio-active molecules were deuterated with good to high deuterium incorporation. Aryl bromides showed a lower reactivity. However, some dehalogenated products could be obtained from aryl bromides with high yields. Secondly, an extension of this dehalogenation reaction, a light-induced alkylation of α-amidyl C(sp3)–H bond was developed. This reaction proceeds through the generation of a α-amidyl radical by 1,5-HAT and its addition on electron-poor olefins. Several 2-iodobenzamides were synthesized from the corresponding amines and 2-iodobenzoic acid. This reaction tolerates several functional groups such as free alcohols or amines. In addition, a wide array of Michael acceptors, such as vinyl sulfones, acrylates or vinyl phosphonate, can be used. Finally, studies about new cyclic boronium species were started. Preliminary results on their stability and reactivity were obtained.

Liste des publications associées :
Photoinduced reduction and deuteration of aryl halides with NHC-boranes. Lalande, G.; Pinet, S.; Robert, F.; Chabaud, L.;* Pucheault, M.* Eur. J. Org. Chem. 2025, e202500543.
Selective Photoinduced α-Amino C(sp3)–H Alkylation Mediated by NHC–Borane. Lalande G.; Chabaud, L.; Pucheault, M. Adv. Synth. Cat. 2026, e70742

Doctorat sous la direction des Drs Alexis Mifleur et Jean-Claude Berthet.

Titre : Synthèse d’hydroboranes et de borohydrures par hydrogénolyse pour le stockage de l’hydrogène.

Date : 10 novembre 2026.
Composition du jury : Guillaume Berionni, Laurent Chaubaud, Arnaud Voituriez, Umit B. Demirci, Parviz Hajiyev.

Résumé :
To reduce anthropogenic CO2 emissions, which have harmful effects on the environment, an energetic transition is needed. Hydrogen has emerged as a key actor, as it can be produced and used in a decarbonised way. Solid-state hydrogen storage is envisaged today, as it offers benefits such as greater compactness and safer handling. Boron compounds such as NH3·BH3 or LiBH4 have shown excellent performance in this field. However, once dehydrogenated, they cannot be regenerated, and their synthesis requires energy-intensive processes. In this thesis, we have studied alternative synthetic pathways for the generation of hydroboranes and borohydrides while exploring BCl3 reactivity. Our first study focused on a new reactivity between a hydrosilane and BCl3 in the presence of chloride ions Cl– to generate BH4– in good yields. A strategy was developed to recycle the chlorosilane formed using H2 as a reductant and to valorise the boron hydrides produced. Mechanistic studies were conducted by combining an experimental approach, involving stoichiometric reactions and kinetic measurements, with a theoretical approach using DFT calculations. A second study utilised the Lewis-acidic properties of BCl3 to abstract hydride from organic compounds, such as tertiary amines, with the aim of synthesising BH3. Lastly, the use of hydroboranes for P–H bond synthesis has also been investigated.

Liste des publications associées :
Brevet N°FR2509973, déposé le 2 sept. 2025 intitulé : « Synthèse de borohydrures à partir d’hydrosilanes »

Doctorat sous la direction des Drs Morwenna PEARSON-LONG, Fabien BOEDA et Philippe BERTUS à l’Institut des Molécules et Matériaux du Mans (IMMM)

Titre : Double addition d’organométalliques sur des dérivés d’acides. Vers la synthèse de carbinamines tertiaires.

Résumé :
The tertiary carbinamine moiety is present in various bioactive molecules, such as alkaloids, and constitutes the structural core of quaternary amino acids. The synthesis of such scaffold bearing aryl, alkenyl, or alkynyl substituents remains challenging using classical methods. Based on previous results concerning the double addition of Grignard reagents onto nitriles, two new approaches to build this kind of highly functionalized structure were developed. In the first part, the behavior of organoaluminum reagents towards acyl cyanohydrins was explored. In particular, the dimethylalkynylaluminums scarcely studied with nitriles were shown to be very selective, opening access to substituted diethynylcarbinamines in high yields and excellent chemoselectivity (>20 examples). Stereoselective control by a sequenced di-addition protocol was evaluated and remains limited at the time. In the second part, the reactivity of organomagnesium reagents with another type of nitrogen-containing acid derivatives close to esters was studied. Different N-substituted imidates were thus evaluated and a judicious choice of experimental conditions allows to carry out the addition of two Grignard reagents with different reactivities to access chiral N-tosylamines. Finally, an asymmetric version was considered from N-tert-butylsulfinylimidate to lead to secondary carbinamines in a diastereoselective manner.

Liste des publications associées :
Double addition of organoaluminum reagents onto nitriles to access diethynyl carbinamines H. G. Nguyen, F. Boeda, P. Bertus,* M. S. M. Pearson-Long* Org. Biomol. Chem. 2025, 23, 7697–7701 : https://doi.org/10.1039/D5OB00911A.

Doctorat sous la direction des Dr Alejandro PEREZ LUNA et Pr Franck FERREIRA.

Titre : New Radical Based Strategies for C-Ge Bond Formation.
Date : 12 décembre 2025.

Composition du jury : Prof. Muriel DURANDETTI; Dr. Luc NEUVILLE; Prof. Guillaume PRESTAT; Prof. Franck FERREIRA; Dr. Alejandro PEREZ LUNA.

Résumé : This thesis investigates the functionalization of alkenes via germanium-centered radicals in copper-catalyzed transformations, focusing on novel C(sp2)-H germylation and intramolecular difunctionalization processes, alongside the more established yet limited hydrogermylation of alkenes. The synthesis of “germanium building blocks” is also addressed, highlighting ongoing challenges in accessibility and structural diversity. Overall, this work broadens the synthetic utility of organogermanium chemistry and provides a foundation for future developments in copper-catalyzed, germanium-radical-based alkene transformations.

Liste des publications associées : Di-tert-Butyl-Peroxide–CuI Promoted Radical Hydrogermylation of Alkenes. L. Lorenzini, A. Barbero, R. Blieck, F. Ferreira*, A. Perez-Luna.* European Journal of Organic Chemistry, 2026, 29, e202501041.

Doctorat sous la direction du Dr Daniel Müller à Institut des Sciences Chimiques de Rennes

Titre : Formation de liaisons carbone-carbone par couplage cationique

Résumé :
The chemistry of stabilized carbocations is well explored, however the reactivity of unstabilized tertiary aliphatic carbocations with organometallic reagents remains underdeveloped. To address this shortcoming, Friedel–Crafts-type reactions between tertiary alkyl chlorides and silylated alkynes were reinvestigated. Optimization of reaction parameters allowed significant extension of the previously reported scope, including tolerating an important number of functional groups and for the first time exploring diastereoselective cation sp-sp3 coupling reactions. Furthermore, two complementary approaches were established for the synthesis of E-configured alkenyl chlorides: InCl3-catalyzed coupling of tertiary chlorides with silylated alkynes, and FeCl3-promoted reactions of tertiary alcohols with terminal alkynes. Alkenyl chlorides are versatile products which can undergo many subsequent transformations as exemplified by elimination, Suzuki coupling and halogenation reactions. In parallel, advances in alkynone synthesis addressed the drawbacks of the classical Birkofer method by employing catalytic FeCl3 with acetic anhydride as both acylating agent and solvent, enabling efficient, mild, and environmentally sustainable transformations.

Liste des publications associées :
Al(III)-Promoted Formation of All-Carbon Quaternary Centers from Aliphatic Tertiary Chlorides and Alkynyl Silanes P. Charki, D.S. Müller J. Org. Chem. 2024, 89, 10, 7324–7329
Utilization of 13C NMR Carbon Shifts for the Attribution of Diastereomers in Methyl-Substituted Cyclohexanes D.S. Müller*, P. Charki, M. Cordier, U. Gellrich*, J. Org. Chem. 2024, 89, 8668–8675
Reactions of Tertiary Aliphatic Cations with Silylated Alkynes: Substitution, Cyclization and Unexpected C−H Activation Products P. Charki, M, Cordier, K. E. O. Ylijoki*, D. S. Müller*,Chem. Eur. J. 2025, e202403979
E-Selective Alkenyl Chloride Synthesis via In(III)- and Fe(III)-Mediated Activation of Tertiary Chlorides and Alcohols P. Charki, D. S. Müller*, ChemistrySelect, 2025, e03325
FeCl3-Catalyzed Synthesis of Ynones from Silylated Alkynes and Acetic Anhydride P. Charki, U. Gellrich*, D. S. Müller*, ChemistryOpen, 2025, e202500402

Doctorat sous la direction du Pr Florence MONGIN et du Dr William ERB à Institut des Sciences Chimiques de Rennes

Titre : Nouvelles bases calcium-lithium pour la fonctionnalisation de composés aromatiques

Résumé :
This work focuses on the synthesis and reactivity study of new calcium compounds, more specifically alkylcalciums and calcium amides. Limited stability but especially high reactivity are direct consequences of the high polarity of the Ca-C and Ca-N bonds. They are therefore ideal reagents to functionalise aromatic compounds. The characterisation of such calcium compounds is not trivial due to this instability, mostly impeding their isolation. Consequently, most of the organocalcium compounds described are stabilised by specific functional groups and/or ligands, which complicates their access routes. While some of the calcium compounds used in this thesis have been isolated, others have been prepared in situ and characterised by NMR experiments at very very low temperature. The behaviour of these new reagents was then studied. The alkylcalciums showed good reactivity in nucleophilic addition, halogen/metal exchange and deprotometallation. Calcium amides were successfully tested in deprotometallation reactions.

Liste des publications associées :
Functionalisation of chromane by deprotonative metallation. Bastien, C.; Erb, W.; Halauko, Y. S.; Matulis, V. E.; Roisnel, T.; Sarazin, Y.; Mongin, F. Eur. J. Org. Chem. 2024, e202400566 (DOI: 10.1002/ejoc.202400566) Investigating di-n-butylcalcium. Duneş, G.; Hédouin, M.; Bastien, C.; Kahlal, S.; Cordier, M.; Erb, W.; Mongin, F.; Saillard, J.-Y.; Oulyadi, H, Sarazin, Y. ChemistryEurope 2025, e202500196 (DOI: 10.1002/ceur.202500196)
Solvated alkali and calcium 2,2,6,6-tetramethylpiperidides: Synthesis and reactivity. Duneş, G.; Bastien, C.; Louis Anandaraj, S. J.; Cordier, M.; Drocet, V.; Roisnel, T.; Erb, W.; Mongin, F.; Sarazin, Y. Eur. J. Inorg. Chem. 2025, e202500451 (DOI: 10.1002/ejic.202500451).