Hydrogenation reactions are among the most employed chemical transformations in academia and industry and have numerous applications. Frustrated Lewis pair (FLP) catalysts, constituted of sterically hindered Lewis acids and bases, have been increasingly applied for performing transition-metal-free hydrogenations of many unsaturated substrates in recent years.
However, several transformations, although well described with transition-metals are still lacking metal free alternatives. The catalytic hydrogenation of unactivated alkenes to alkanes and the reduction of amides to amines, two very desirable transformations, are representative examples. Another longstanding challenge is the catalytic hydrogenation of carbon dioxide with a FLP system, which has only been performed under stoichiometric conditions so far.
My PhD research program targets the development of robust frustrated Lewis pairs catalysts based on new types of rigid and sterically hindered Lewis bases (cage-shaped phosphines named 9-phosphatriptycenes). These phosphines will be designed to have suitable steric and electronic properties for addressing the aforementioned limitations in the field of FLP chemistry.
The first goal of the PhD consists in the development of functionalised 9-phosphatriptycenes that will be combined, in the second part of my project, to a variety of boron-based Lewis acids for hydrogen activation. These processes will be studied by combining experimental mechanistic investigations and state of the art computational methods. In the last and main part of this PhD research proposal, we will take advantage of the particular reactivities of the newly developed FLP systems for the catalytic hydrogenation of unactivated alkenes, amides and investigating the catalytic reduction of CO2 in formic acid, therefore converting a potent greenhouse gas into a useful chemical compound.