Paul CHARKI PhD defense

Formation of Carbon-Carbon bonds by Cationic Couplings
Formation of Carbon-Carbon bonds by Cationic Couplings

Organic Chemistry & Interfaces (COrInt) team

Abstract
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 Econfigured 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.

Jury
Yannick Landais, Professeur, Université de Bordeaux / Reporter
Anne Boussonnière, Maitre de conférences, Le Mans Université / Reporter
Florence Mongin, Professeure, Université de Rennes, ISCR / Examiner
Daniel Müller, Chargé de recherches, ISCR, CNRS / PhD Director

Contacts
Paul Charki, paul.charki@univ-rennes.fr
Daniel Muller, daniel.muller@univ-rennes.fr