Phosphatriptycenes

: from quantum chemical investigations to applications in main group and frustrated Lewis pair chemistry

Abstract

Frustrated Lewis pairs (FLPs) consisting of sterically hindered Lewis acids and bases constitute appealing alternatives to established transition metal catalysts. Expanding the scope of FLP and main group chemistry requires the development of Lewis bases or acids with new reactivities. To this end, constraining main group elements, such as phosphorus and boron, in a “non-classical” scaffold is a promising but little explored strategy. Due to their cage-shaped structure, 9-phosphatriptycene derivatives are weak Lewis bases with high potential in FLP chemistry. Similarly, boranes such as 9-boratriptycene derivatives exhibit an enhanced Lewis acidity due to their non-planar character.
This thesis describes the multi-step synthesis of 9-phosphatriptycene derivatives and their applications in FLP catalysis (hydrogenation of unactivated alkenes) and in main group chemistry (potential fluorinating agents). In addition, a density functional theory investigation was undertaken, focusing on their structure-property relationships as well as on the Lewis acidity of 9-boratriptycene derivatives and their applications in methane activation.
In essence, this work expands our understanding of the structure-property relationships affecting the reactivity of main group compounds. This fundamental advancement demonstrates that structural changes can constitute a new strategy for reactivity fine-tuning and brings solutions to long-lasting challenges in metal-free catalysis and main group chemistry.

Date of Award	22 Jun 2023
Original language	English
Awarding Institution	University of Namur
Sponsors	Fund for Research Training in Industry and Agriculture (FRIA)
Supervisor	Guillaume Berionni (Supervisor), Benoit Champagne (Co-Supervisor), Catherine Michaux (President), Vincent Liegeois (Jury), Olivier Baudoin (Jury) & Lutz Greb (Jury)