Josep Cornella (Max-Planck-Institut)

The success of transition metal catalysis in organic synthesis is rooted in decades of advances in fundamental organometallic reactivity. Bonding theory on d-block elements has allowed synthetic chemists to design novel and powerful catalysts that underpin modern chemical manufacturing. However, the increasing demand, cost, and environmental impact associated with many transition metals highlighted the need for alternatives. To this end, exploration of underutilized regions of the periodic table might reveal unconventional mechanisms inaccessible within established frameworks, making the search for sustainable alternatives a powerful driver of discovery. Beyond the transition metal realm lies a group of elements that have largely been overlooked by the synthetic community: the heavy elements, ignored by many due to the historically bad reputation associated to them. Yet, among them, one can find bismuth (Bi), placed at the fringe of the periodic table, virtually representing the last stable element. Bismuth is the main character of this talk, which will highlight how our laboratory unlocked its potential as catalyst for organic synthesis. Due to the completely distinct electronic configuration, and the extremely large contribution of relativistic effects when compared to earlier p- or d-block elements, a rich redox landscape was uncovered. It will be highlighted how the excellent redox properties of bismuth have found stoichiometric and catalytic applications in various synthetic protocols, photochemistry and small molecule activation. A rational ligand design with an in-depth mechanistic analysis of all elementary steps proved crucial to uncover the intricacies of such a unique element of the periodic table.