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Stereodefined Vinylsiloxanes as a Modular Platform for Nickel-Catalyzed Transformations and Beyond by Logan Salamone -
Lundi 12 octobre 2026 à 16h30 - Auditoire LAVO51 - Bâtiment Lavoisier - Place Louis Pasteur, 2 - 1348 Louvain-la-Neuve -
Transition-metal-catalyzed cross-coupling reactions have become indispensable tools for the construction of carbon-carbon and carbon-heteroatom bonds. Among the various organometallic coupling partners available, organosilicon compounds are particularly attractive owing to their stability, low toxicity, and broad functional-group tolerance. Despite these advantages, the use of stereodefined vinylsiloxanes in catalytic transformations remains largely unexplored, especially in nickel-catalyzed radical processes. The central objective of this thesis was therefore to develop a modular platform of stereodefined vinylsiloxanes and investigate their potential in modern catalytic chemistry, with a particular emphasis on nickel-catalyzed radical reactions.
A stereodivergent metal-catalyzed hydrosilylation strategy was used to prepare β-(E)-, β-(Z)-, and α-vinylsiloxanes from common terminal alkyne precursors. These stereodefined vinylsiloxanes provided a common platform for the catalytic transformations investigated throughout this work.
The compatibility of vinylsiloxanes with nickel-catalyzed radical chemistry was first demonstrated through stereospecific radical cross-coupling (RCC) reactions with pyridinium salts, enabling the preparation of stereodefined alkenes while preserving the stereochemical information welded during the hydrosilylation step. More advanced transformations were subsequently explored, including carbonylative cross-coupling and alkene difunctionalization, providing access to densely functionalized alkenes with excellent stereochemical control.
Finally, the platform was extended beyond nickel catalysis through the development of a copper-catalyzed trifluoromethylthiolation reaction. This method enabled the stereoselective synthesis of (E)-, (Z)-, and (1,1')-SCF₃-alkenes, a class of compounds for which stereoselective methods remain scarce.
Overall, this thesis demonstrates that stereodefined vinylsiloxanes can participate in diverse nickel- and copper-catalyzed transformations while preserving the stereochemical information welded during the hydrosilylation step, even under radical conditions. Starting from common terminal alkynes, this approach provides access to several families of stereodefined molecules and highlights the potential of vinylsiloxanes as versatile synthetic intermediates in organic synthesis.
Jury members :
Prof. Olivier Riant (UCLouvain, Supervisor)
Prof. Jean-François Gohy (UCLouvain, Chairperson)
Prof. Raphaël Robiette (UCLouvain, Secretary)
Prof. Ludovic Troian-Gautier (UCLouvain)
Prof. Gwilherm Evano (Université Libre de Bruxelles)
Prof. Nicolas Blanchard (Université de Strasbourg)
Pay attention : the public defense of Logan Salamone will also take place in the form of a videoconference
