Periodic Reporting for period 1 - B-yond (Reprogramming the reactivity of main-group compounds for capturing and activating methane and dinitrogen)
Reporting period: 2022-10-01 to 2025-03-31
In contrast to chemical reactions mediated by transition-metal catalysts, known for more than a century, the last decade has witnessed spectacular developments in the emerging area of catalysis mediated by non-metallic species (organocatalysis, organic photocatalysis and main-group catalysis).
Among these novel catalysts based on abundant and inexpensive main-group elements, frustrated Lewis pairs and geometrically constrained element/ligands bifunctional systems are increasingly investigated. These ground-breaking catalysts containing s- and p-block elements are revolutionizing the field of metal-free catalysis and are driving an increasing number of sustainable and cost-effective catalytic processes.
Besides increasing the variety of main-group catalysts employed as alternative to transition-metal complexes for molecules functionalizations, the emerging area of geometrically constrained catalysts is providing completely novel solutions for chemists to reach new reactivities, beyond the current state-of-the-art.
The main objective of this project is to re-program of the reactivity of main-group compounds from the groups XIII and XIV of the periodic table of elements, by exploiting original concepts (low reorganization energy, curved main-group scaffolds, geometrical distortion and structural deformation, etc) towards new metal free catalyst development strategies.
In this project "B-yond", new molecular engineering strategies have been applied to develop unprecedented main-group catalysts embedded in cage-shaped and curved molecular scaffolds with significant geometrical distortion, such as the triptycene three-dimensional scaffold. This results in highly reactive catalysts based on non-planar acids and superacids with unmatched reactivities based mainly on the B, Al, C and Si elements, that defy established structural theories. By pushing the boundaries of knowledge of chemical bonding and exploring unusual ligands-elements bonding situations and advancing the design of main-group catalysts beyond the state-of-the-art, unprecedented C-H bond functionalization processes are developed and exploited for hydrocarbons transformation through the concept of “low reorganization energy catalysis”. The activation of even more inert molecules with unique main-group superacids and bases will be tackled in the next steps.
Expected impacts :
The project B-yond is successively addressing four key challenges in main-group and coordination chemistry for enabling the development of new powerful methods for the activation and functionalization of C-H bonds in hydrocarbons, for the electrophilic C-H borylations of arenes and alkanes, for the hydrogenation reactions of unactivated alkenes, and for the trapping, activation and transformation dinitrogen. Inspired by transition-metal catalysis and stoichiometric main-group chemistry, B-yond will “reprogram” the reactivity of s and p block elements to overstep the current chemistry rules, based on innovative emerging concepts.
Innovative catalytic cycles are being developed for key chemical transformations widely used in industrial setups (hydrogenations, C-H borylations, electrophilic fluorinatins, etc) and applied in challenging chemical processes. The development of ground-breaking main-group catalysts based on the most abundant elements in the earth crust will have a future impact on chemical energy transformation and storage, as well as on bulk and fine chemical synthesis. The entire chemical community will benefit from the research findings that will lay the basis for developing new energy and resources management strategies, notably through novel approaches to catalysts design and sustainable materials development.
Among these novel catalysts based on abundant and inexpensive main-group elements, frustrated Lewis pairs and geometrically constrained element/ligands bifunctional systems are increasingly investigated. These ground-breaking catalysts containing s- and p-block elements are revolutionizing the field of metal-free catalysis and are driving an increasing number of sustainable and cost-effective catalytic processes.
Besides increasing the variety of main-group catalysts employed as alternative to transition-metal complexes for molecules functionalizations, the emerging area of geometrically constrained catalysts is providing completely novel solutions for chemists to reach new reactivities, beyond the current state-of-the-art.
The main objective of this project is to re-program of the reactivity of main-group compounds from the groups XIII and XIV of the periodic table of elements, by exploiting original concepts (low reorganization energy, curved main-group scaffolds, geometrical distortion and structural deformation, etc) towards new metal free catalyst development strategies.
In this project "B-yond", new molecular engineering strategies have been applied to develop unprecedented main-group catalysts embedded in cage-shaped and curved molecular scaffolds with significant geometrical distortion, such as the triptycene three-dimensional scaffold. This results in highly reactive catalysts based on non-planar acids and superacids with unmatched reactivities based mainly on the B, Al, C and Si elements, that defy established structural theories. By pushing the boundaries of knowledge of chemical bonding and exploring unusual ligands-elements bonding situations and advancing the design of main-group catalysts beyond the state-of-the-art, unprecedented C-H bond functionalization processes are developed and exploited for hydrocarbons transformation through the concept of “low reorganization energy catalysis”. The activation of even more inert molecules with unique main-group superacids and bases will be tackled in the next steps.
Expected impacts :
The project B-yond is successively addressing four key challenges in main-group and coordination chemistry for enabling the development of new powerful methods for the activation and functionalization of C-H bonds in hydrocarbons, for the electrophilic C-H borylations of arenes and alkanes, for the hydrogenation reactions of unactivated alkenes, and for the trapping, activation and transformation dinitrogen. Inspired by transition-metal catalysis and stoichiometric main-group chemistry, B-yond will “reprogram” the reactivity of s and p block elements to overstep the current chemistry rules, based on innovative emerging concepts.
Innovative catalytic cycles are being developed for key chemical transformations widely used in industrial setups (hydrogenations, C-H borylations, electrophilic fluorinatins, etc) and applied in challenging chemical processes. The development of ground-breaking main-group catalysts based on the most abundant elements in the earth crust will have a future impact on chemical energy transformation and storage, as well as on bulk and fine chemical synthesis. The entire chemical community will benefit from the research findings that will lay the basis for developing new energy and resources management strategies, notably through novel approaches to catalysts design and sustainable materials development.
The synthesis of pyramidal triptycene molecules with Si (silicium-triptycene) has been achieved and collaborative work with European experts on silicium chemistry has been initiated for investigating their reactivities, electrophilicities and their potential applications in catalysis. This is a huge achievement, because the family of pyramidal triptycene Lewis acids is widening to group XIV elements and will lead to a whole new class of Lewis superacidics. These species are critical for the final workpackages of the B-Yond project in the next two and a half years.
For the first steps of the project, a deep understanding of the reactivity and steric hindrance of Lewis bases (pyridines and phosphines) was required. We have been able to parametrize nearly a hundred of two and three-dimensional pyridine derivatives. This was our most impactful primary research article in 2024 related to the ERC project. New phosphorus Lewis base chemical species are currently parametrized and will be published in 2025.